4 Best Composting Toilets – Reviews for 2019

If you’re looking for an eco-friendly substitute to conventional flush toilets, then a composting toilet could be the right fit for you. This type of toilet gets the job done without the use of water or plumbing, minimizing the negative impact it has on the environment.

An efficient composting toilet wouldn’t be possible without the use of advanced, innovative technology. Composting toilets are constructed to be self-contained, allowing you to install them in nontraditional places like boats, RVs, tiny houses or cabins. This article will review a selection of top composting toilets, providing you with information on their functionality and features. We’ll also go over composting toilet brands, installation information, and maintenance tips.

Although composting toilets are more expensive than their traditional flush toilet counterparts, the benefits a composting toilet provides justifies the price tag. The most notable benefits include the ability to operate without plumbing and the potential to be installed just about anywhere.

For nomadic types who are always on the move, composting toilets are an attractive choice. The eco-friendly and self-sufficient functionality enables you to create a comfortable restroom anywhere. A cabin in the woods, homestead, camping site – no matter the location, a composting toilet can be a feasible amenity.

Top 4 Best Composting Toilet Reviews

1. Nature’s Head Self-Contained Composting Toilet

With an impressive Amazon rating and a comparatively low price tag, this Nature’s Head composting toilet is a well-rounded option. The thoughtful, advanced construction includes space-saving solutions to make the toilet appropriate for many living situations.

This eco-toilet doesn’t need a sewage connection or a water supply to operate, so installation is simple. Connecting the hose to open air for ventilation and connecting electricity to work the fan are basically the only steps involved in installation. Other than the outside vent, the product comes included with all you need for installation. Initially intended for marine purposes, this portable toilet has every feature you’ll want without taking up very much space.

Having been designed with marine life in mind, this waterless toilet lend itself well to the small, bumpy conditions of trailers and RVs. It has the sturdiness you need for life on the go.

The compost bin for solid waste is set up with peat moss for decomposition. It’s advertised that the bin can go for 90 uses before getting emptied – it can actually go for a longer period of time than that.

Taking out the waste bins for emptying is a simple process. The liquids tank has a few clips at either side – simply unhook them and lift the tank out using the convenient handle.

Convenient for small spaces, there’s an agitator handle (which is also called a spider handle), at the side of the solids bin to mix the compost. To give you flexible installation options, the handle can be mounted on either side of the toilet. The ventilation hose can be mounted on either side as well, making the installation process easier overall.

When it comes to affordability, user-friendly features, and efficiency, this Nature’s Head toilet nails it. It’s space-saving, great for the environment, and promotes energy efficiency.

Main Features:

  • Durable polyethylene construction
  • Separate bins for liquid and solid waste
    • easy to remove and empty
    • zero odors
    • high-capacity
  • Compact spider handle
  • Disassembles easily
  • Included fan and vent hose for neutralization
  • 5-year warranty
  • Extensive customer support
  • Measures 21.5” high, 18” wide, 17.75” long
  • Weighs 28 pounds.

2. Nature’s Head Dry Composting Toilet

This composting toilet from Nature’s Head is similar to the toilet from the same brand listed above in both cost and features. The two models differ mainly in the agitator handle; this dry composting toilet uses a standard handle that, instead of saving space like the model above, add roughly two inches to the toilet’s width. Although the larger handle takes up more space, it’s also faster and more convenient to use.

The choice to use an electric fan with this model is great if the ventilation shaft stretches to a length over 5 feet or has curves. You’ll need to use an adapter if you’re using a 110V power source, although the fan itself doesn’t use very much power.

This Nature’s Head dry composting toilet is still compact despite the standard handle and is quite sturdy, making it great for use in boats, RVs, and trailers. The additional width compared to the other similar Nature’s Head toilet is notable, but it’s still an awesome choice for life on the move.

Main Features:

  • Uses no water
  • Simple disassembly for emptying
  • Sturdy polyethylene construction
  • Separate bins for liquid and solid waste
  • Included fan and vent hose
  • 5-year warranty
  • Extensive customer support
  • Measures 21.5” high, 20.75” wide, 17.75” long
  • Weighs 28 pounds.

3. Sun-Mar Excel Self-Contained Composting Toilet

Requiring no water and emitting no odors, this composting toilet from Sun-Mar is just one example of the excellent products put out by this trusted brand. It’s an ideal toilet for when you need to create a bathroom in a remote location, bringing comfort to a transient lifestyle.

This off-grid toilet has two different bins for liquid and solid waste. Toilet paper can be decomposed without trouble. The solid waste bin, when regularly used by two to three people, needs to be taken out after roughly a month.

To easily fit into narrow spaces, this waterless composting toilet has the handle at the front as opposed to the side. The construction is streamlined and compact for use in a variety of different locations and situations.

This Sun-Mar composting toilet is NSF certified – this certification required continual maximum capacity testing for six months. During the testing, it produced sanitary compose and emitted no unpleasant odor. This dry composting toilet is built to handle heavy use; it’s ideal for a two to three-person residential household or a five to seven-person vacation/weekend home.

Installing the Sun-mar Excel is simple; all you need to do is hook up the ventilation vent. You can use an electric fan to improve the efficiency of odor-elimination if the vent has bends.

A mixture of peat and microbe, which is included with the toilet, needs to be put in the compost bin before the first use to aid in decomposition. To dump the solids bin when it’s full, simply use the convenient sliding tray. The peat mixture must be regularly mixed in with the compost using the handle for maintenance.

Main Features:

  • Waterless composting toilet
  • Medium/large capacity
  • Liquid and solids bins are separate
  • Tank is constructed of lightweight fiberglass
  • Included ventilation kit
  • Components are NSF/ANSI certified
  • Can fit into narrow spaces with the front-located agitator handle
  • Includes a detachable footrest
  • 5-year tank warranty and 3-year parts warranty
  • Measures 32” high, 22.5” wide, 33” long with footrest
  • Weighs 50 pounds

4. Sun-Mar Compact Self-Contained Composting Toilet

This portable composting toilet from Sun-Mar is a compact model that’s ideal for one to two users. The streamlined design is better-looking than many of its competitors. The compact, low-profile design is possible with the patented Bio-drum from Sun-Mar, which is larger at the back and smaller at the front. To mix the drum, there’s a single agitator handle which extends from the front of the toilet. The handle goes back into the toilet when not in use to save space. The dimensions of this self-composting toilet are great for narrow areas, but not ideal for spaces lacking in length.

Main Features:

  • Uses no water (dry composting toilet)
  • Compact and elegant layout
  • Fights odors
  • Innovative, patented Bio-drum
  • Recessed handle that operates from the front
  • Non-polluting, water-free, and utilizes regular household current
  • Measures 28” high, 22” wide, and 33” long
  • Weighs 50 pounds

What is a Composting Toilet?

Composting toilet is an eco-toilet that both save water and make use of waste by creating, you guessed it, compost. These toilets use only a small amount of water, if any at all, to flush out the waste. To eliminate the waste, it’s combined with either peat moss or sawdust and microbes, creating an entirely safe fertilizer. This process involves aerobic action to turn the waste into compost.

To curb odors and create compost as effectively as possible, composting toilets divide liquid and solid waste, storing the two in separate containers. The liquids container can typically detach and slide out to be transported using a handle. You’ll need to empty the liquids container more often in order to prevent unpleasant odors, but the modern construction of composting toilets makes doing so simple. The solid waste container holds the actual compost and doesn’t need to be emptied as often as the liquid. This section can go for months without emitting any odor, unless the compost mixture gets wet.

Places that don’t have access to a water supply or drainage system are where you’ll most commonly find composting toilets. As mentioned previously, these toilets are an ideal choice for boats, RVs, and camping.

How Does a Composting Toilet Work?

For a composting toilet to work safely and effectively, the conditions must be such that the waste can decompose. Essentially, the process for composting waste in a toilet is the same as in a garden composter; the two differ only in the type of waste that’s composted. For waste to process and become compost, the following points must be addressed:

  1. The conditions that the waste is under needs to be optimal for fast decomposition.
  2. There must be a vent system so that all of the water in the waste can evaporate, thus ridding the waste of odors. Waste is 90% water, so the evaporation process is very important.
  3. When the waste has decomposed, the resulting compost needs to be safe to handle. Otherwise, a composting toilet simply wouldn’t be a practical option. This is why composting toilets are designed to be user-friendly, sanitary, and simple to maintain.

Once the waste from a composting toilet has completely decomposed, you’ll end up with a compost mixture that’s completely dry and has no smell. The compost is comparable to fertilizer that you can purchase at home and garden retailers. You can make use of the compost in your garden for non-edible plants – just make sure to check your state’s regulations before burying it. People love that they can use the compost from their composting toilets to augment garden fertilizers.

Do Composting Toilets Smell?

If you’re skeptical of composting toilets because you’re worried about odors, you’re certainly not alone. The concept of human waste sitting in the bathroom for prolonged periods of time is enough to make anyone second guess. However, this is an unfounded fear when it comes to composting toilets. When manufactured and installed correctly, composting toilets are completely sanitary and have zero odor. Advanced airflow structures and strong seals eliminate odors instantly. Some homeowners in suburban areas have even chosen to install composting toilets for the environmental benefit – that’s how well this type of toilet can neutralize odors.

Types of The Composting Toilets

Not all composting toilets are the same. The main difference between various models is whether the composting unit is contained within the toilet itself (self-contained composting toilet) or whether it’s separate from the toilet (remote or central composting toilet system). A selection of composting toilets has a heating unit that’s used to speed up the decomposition of the waste. Composting toilets can work fine without heating, but it’s a great addition to improve the toilet’s overall functionality. For complete efficiency in all composting toilets, there should be a fan that operates with a power supply to get rid of unwanted odors and gases.

Composting toilets can vary in power supply type. A regular 110V mains power supply or a vehicle 12V supply are two common options. In highly advanced models, solar cells are used to supply electricity to the toilet. The use of solar power allows a toilet to be completely self-reliant and as eco-friendly as possible.

Some composting toilets use natural decomposition instead of electricity. These models aren’t workable for most individuals because they require a certain amount of appropriate land to function properly.

Slow Composting Toilets

Slow composting toilets have a slow composting process, as you would guess by the name, and therefore need less maintenance and general effort by the owner. This type of composting toilet is more widely used than other options because of they are comparatively easy to use and practical.

The waste in slow composting toilets must decompose for a long stretch of time before becoming safe and usable compost. The composting process will last for a few months before the harmful microorganisms in human waste are fully killed. However, roundworm, a highly dangerous microorganism, can take as many as ten years to be destroyed. Slow composting toilets have a long decomposition process because the temperature is lower than in a garden pit, where composting occurs faster.

Note that it’s recommended to use the compost from this type of toilet on non-edible plants instead of edible ones in your fruit or vegetable garden. This is to ensure that harmful bacteria that may not have died off in the decomposition process don’t end up in your food. Slow composting toilets are an ideal choice for people who want very easy maintenance – the waste chamber generally doesn’t need to be emptied for two years or more.

Active Composters

Active composting toilets come in two varieties:

  1. Self-contained system.
  2. Remote system.

With a self-contained toilet system, composting occurs within the actual toilet. The process can involve heaters and exhaust fans to quicken the decomposition process if you choose. Sawdust is generally added to the compost by users to help neutralize unpleasant smells and reduce moisture.

With a remote system, toilets have a separate composting bin that’s located outside the toilet. The bin can be a hole in the ground underneath the toilet or one close to a garden. Active composting toilets take more effort from the user than slow composting options because the waste needs to be continually moved to the composting bin. The user must also keep an eye of the toilet to make sure the waste gets completely flushed every time. To flush everything out, a small amount of water, if any at all, can be used; a vacuum is another way to make sure the bowl gets clean.

This type of toilet is appropriate for larger households of over three people. This is because there’s more space for waste storage.

Composting Toilet Installation

To install a composting toilet, you just need to attach two brackets to the floor to keep the toilet in the desired spot. To operate the electric fan and heater (if included), a 12V or 110V supply of electricity will be needed as well. If your toilet also includes a pipe to further curb odors and vent out gasses, you’ll probably need to have a hole drilled so that the pipe is exposed to open air.

Before being fully ready to use, sawdust or peat moss must be added to the composting area. The right amount of sphagnum peat moss or coconut fiber for most toilets is roughly two gallons. Make sure that the moss isn’t too wet, just damp and no longer crumbly. Add a bit of water to dampen the peat moss if it’s completely dry.

You may be dreading emptying the compost bin, but in truth, the odors are neutralized by the time it needs emptying, so the task is not bad at all.

Composting Toilet Maintenance

To properly maintain your composting toilet, make sure you do these few things:

  1. Turn the handle each time solid waste is added to the compost bin.

Giving the handle a turn will mix the waste and the moss to move along the composting process.

  1. Keep an eye on the solids and liquid bins for emptying.

The liquids bin has a capacity of around two gallons, usually needing to be taken out every few days. In contrast, the solids bin can last for longer stretches of time before needing emptying – it depends on how many people are in your household and how often the toilet is used.

  1. After emptying the solids bin, add the peat moss mixture before the next use.

These maintenance steps are the same or almost the same for all of the composting toilets available on the market. Maintenance for these eco-friendly toilets only varies in how the bins are detached for emptying and how the solid waste is mixed.

The Composting Toilet – Preparing and Emptying

Since composting toilets don’t use water for flushing, the dumping process takes more effort than a traditional flushing toilet. To streamline the maintenance of your composting toilet, adhere to the information given below.

Preparation Prior to Use

To help the composting process, the toilet needs to be set up with a special mixture. This typically includes either sphagnum moss or coconut coir, as mentioned earlier. These materials are inexpensive and can be easily found at home and garden store like Home Depot or Lowe’s, or online warehouse sites like Amazon.com. Buying from online retailers is especially convenient because the composting mixture will be delivered to your door.

To use, the moss or coconut coir must be damp, but not wet, so that it no longer has a crumbly texture. When adding the mixture to the composting bin, make sure it fills the bin under the level of the agitator handle.

Emptying a Composting Toilet

The two bins in a composting toilet, solids and liquids, need to be emptied in different ways. Make sure the waste is properly dumped with these tips:

The Solids Bin

For a composting toilet that’s regularly used by two people, the solid waste bin will need to be taken out approximately every three weeks, according to a Nature’s Head estimate. You’ll know the bin needs to be dumped when it’s markedly full or when it becomes hard to turn the agitator handle.

Before dumping, you want to make sure the waste has had time to begin the composting process. So, wait a minimum of 6 hours, but ideally around 12 hours, to take out the bin after the last solid addition. To make this possible, it’s a good idea to get an alternate solids bin so that you can continue to use the toilet while the full solids bin is composting.

The actual dumping process will vary depending on the toilet. For Nature’s Head toilets, use a 13-gallon trash bag (a biodegradable bag works the best) to cover the top of the bin, then empty in the waste.

Don’t use the composted waste for edible plants just after emptying the bin. You need to wait roughly a year to allow all of the microorganisms to die. The waste can be added to a traditional compost bin to continue to decomposition process. Also, double check your state’s laws about dumping this type of waste and comply with all regulations.

The Liquids Bin

Liquid waste tanks have approximately a 2-gallon capacity. This will hold around 3-4 days’ worth of liquid waste for Nature’s Head toilets when 2 people are using the toilet. It’s simple to monitor the fullness of the liquid tank because it’s translucent.

As with the solid waste bin, it works best to have a spare liquid tank to make emptying easy. You’re not always in the best place to dump the waste, so it’s convenient to be able to keep using the toilet with the spare tank when the main tank is full.

Transporting the liquids tank is made simpler with the built-in cap. You can add urine to plants because it’s an effective fertilizer, but, again, make sure you’re complying with the laws of your state as you do so.

Composting Toilets Pros and Cons


  • These toilets use very minimal electricity.
  • Water isn’t needed for flushing, which will cut down on your household’s overall water usage and the need to dispose of wastewater.
  • Using compost from the toilet as fertilizer for non-edible plants is a great, organic way to take care of the garden.
  • You can create a bathroom in a remote location with a composting toilet.
  • Self-contained composting toilets eliminate the need to transport the waste for dumping or treatment.
  • You can also use the composting toilet to compost kitchen scraps.
  • When you install a composting toilet, you can often install a smaller leach field at a more affordable rate, although this varies state by state.


  • Composting toilets are more expensive than regular flushing toilets and may not fit into everyone’s budget.
  • Keeping up with composting toilet is a responsibility that requires time and effort. Both the owner and the users of the toilet need to be aware of how to properly use and maintain the toilet.
  • If incorrectly maintained or carelessly installed, emptying the waste bins of a composting toilet can be a highly undesirable task.

Composting Toilet Tips

Unpleasant odors, flies, and other issues shouldn’t occur so long as you use a composting toilet properly. Follow these tips to make sure you don’t run into problems.

  • The liquid waste must remain separate from the solid waste. The composting process can’t occur if the two wastes mix; when the solid waste is exposed to liquid, it will emit an odor.
  • Always close the lid of the toilet when it’s not being used. Bugs won’t be able to enter the toilet and the vent system will be able to work correctly.
  • The recommended sphagnum peat moss can be purchased at Home Depot or Lowe’s for around $10 per bag. A bag typically lasts for a year.
  • Always turn the agitator handle a couple of rotations after depositing solid waste to help along the process of composting.
  • Toilet paper will decompose slower than the other wastes in the compost bin, but it can certainly be added.
  • If the urine tank emits an odor, you can dilute it with white vinegar.
  • To prevent the mixing of waste types, seated usage is highly suggested.

Purchasing a Composting Toilet: What to Keep in Mind

Upkeep and Capacity

Composting toilets vary in the effort required by the user for maintenance. There are also different composting toilets for different household sizes. It’s important to consider your personal situation to find the right off-grid toilet for you. Some people want the toilet to be as easy to maintain as possible, while others prefer to be involved and carefully monitor the composting process.

It’s also crucial to note how often the toilet will need to be emptied. This will depend on how often the toilet is used. Look for a toilet with a larger capacity if a high number of people will be using it.


Composting toilets need a ventilation system to keep odor in check. A ventilation shaft goes from the toilet to the area outside of your house. While it’s best to not have a fan on at all times, one can be used to make the ventilation system more efficient.


Before purchasing a composting toilet, ensure that you have the space to accommodate it. Composting toilets take up more room than traditional toilets. To mix the compost, these toilets have a handle reaching out from the front or the side. Additional space in the bathroom is needed to easily turn this handle. Find out what dimensions are available in your bathroom before settling on a specific model. Especially for mobile homes, such as trailers, RVs, and tiny houses, space needs to be carefully allocated.


All of the composting toilet models listed in this article need an electricity source to run – this is quite common among composting toilets in general.

That being said, if you’re in a location that can’t provide a reliable electricity source, you do have other options. There are composting toilets, such as the Separett Villa 9210 DC/AC, that can operate with solar power or a battery. Also, there are non-electric composting toilets from manufacturers including Sun-Mar (Sun-Mar Excel NE).

Laws and Regulations

Composting toilets haven’t been around very long and the practice of composting that type of waste isn’t yet widely accepted. Laws that govern waste disposal vary depending on location, and some states haven’t legalized the process of composting human waste, even when it’s hygienically treated.

Before getting a composting toilet, check to make sure that the disposal of the waste is legal for your region. If you own your own land in a rural location, this shouldn’t be an issue for you. Inhabitants of urban and suburban areas will have more trouble owning a composting toilet simply because the regions are more populated – the area in which you compost the waste may be close to or shared with a neighbor, so their needs must be taken into consideration.

Best Composting Toilet Brands


Sun-Mar specializes in composting toilets, providing some of the best products available and excellent service to customers everywhere. This company helps out their customers with instructional blogs and useful videos to improve the ease-of-use of their toilets. The Sun-Mar customer base is diverse, including numerous media outlets and programs. Sun-Mar toilets have even made an appearance in outer space!

The company was founded by Hardy Sundberg. They developed the first self-contained toilet in 1971, making the Sun-Mar name consistent with innovation. However, Sun-Mar has competitors, including Nature’s Head, despite the small scale of the composting toilet market. Sun-Mar products are undoubtedly exceptional, but the brand isn’t the current market leader.

Nature’s Head

Nature’s Head is a top composting toilet brand, prioritizing advanced features and incredible affordability to keep their products at the head of the pack. The greatest asset of Nature’s Head toilets is ease-of-use at an attainable price. Consumers on a budget don’t have to sacrifice a quality toilet for an affordable price with Nature’s Head.

Nature’s Head toilets come with a 5-year warranty, which is longer than every other option listed. This not only gives the customer peace of mind, but also displays the confidence that the brand has in its products.

Nature’s Head composting toilet have a look that’s like that of a traditional toilet. This adds a great level of comfort, but may make the toilet harder to fit into small spaces.

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