Best Composting Toilets 2021 | Toilet Reviews

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With the increased popularity of tiny homes and living off the grid, composting toilets are becoming more popular. Even those who live with indoor plumbing are opting to switch to using central or self-contained composting toilets. The idea of recycling even your bodily waste makes it the ultimate switch for those who want to give zero waste, sustainable, and self-sufficient lifestyles a shot.

If you’re researching one, we’ve come up with this comprehensive guide that can help you weigh your options and see for yourself which kind and product will suit you best.

At my parent’s remote cabin in northern Minnesota, over the years we’ve tried several composting toilets. Starting with a simple “bucket” style toilet on a 5-gallon bucket. We later upgraded to a Sun-Mar composting toilet and just recently, after 25 years, replaced it with this Nature’s Head Composting Toilet.  The cabin is off-grid, too remote and the ground is too rocky (glacial limestone ledge rock) to dig a septic system.

But that’s not the only quality option on the market, continue reading below to see detailed reviews for all the composting toilets we reviewed.

Best Composting Toilets

Nature’s Head Self Contained Composting Toilet (Spider Handle Design)

Nature's Head Self Contained Composting Toilet with Close Quarters Spider Handle Design
Nature’s Head Self Contained Composting Toilet (Image: Amazon)

Self-contained composting toilets might seem like they’re glorified dump buckets, but this isn’t the case. This Nature’s Head toilet will clearly tell you that this type of composting toilet can look a lot like a regular commode so you won’t have to feel weird or be uncomfortable in using it.

Equipped with a full-sized elongated seat for your comfort, you won’t feel any different while sitting on this throne. Its detachable base serves as its very own composting tank with a urine bottle at the front to effectively separate liquid and solid wastes.

It also has a vent pipe with a small fan powered by a 12V battery to ensure ample oxygen supply to the accumulated waste and encourage degradation.

What really makes this toilet different is its spider handle design. A hand crank on the side will let you use this handle to mix waste and peat moss inside the chamber.

This will ensure proper waste decomposition and effective odor elimination. Scroll down to compare to the standard crank model by Nature’s Best.

Designed and made by sailors, you can also count on this product to be very durable.


  • Made in the USA
  • Durable
  • Comfortable seat
  • Urine separating
  • Portable
  • Easy to maintain
  • Requires emptying after 80 uses


  • One of the most expensive composting toilets on the market
Nature's Head Self Contained Composting Toilet with Close Quarters Spider Handle Design
Nature’s Head Toilet Diagram

Sun-Mar Excel Composting Toilet

Sun-Mar Excel Non-Electric Self-Contained Composting Toilet, Model# Excel-NE
Sun-Mar Excel Non-Electric Composting Toilet (Image: Amazon)

Sometimes access to electricity is completely impossible, especially when you absolutely want to stay off the grid, so electric-powered commodes just won’t cut it.

To provide a fantastic alternative, Sun-Mar has created the Excel Non-Electric Self-Contained Composting Toilet

This product performs just as well as other composting toilets on the market today without the need for a battery. Without an airing and heating device, it’s designed to function just like a chimney.

With a vent that is supposed to be installed vertically and extend up to 2’ to 3’ above the highest point of your roof, it mimics a chimney’s engineering. However, should you need to add a curve to the vent pipe, you’ll need to add an optional 12V fan.

Designed with your comfort in mind, the seat has a good height so you don’t have to sit too low to the ground. It even comes with an attached footstool for small users. You also won’t have to struggle in emptying and cleaning this unit as the compost tray is easily accessible.


  • Large capacity
  • Non-electric so no need to worry about powering it up
  • ½” drain to prevent overflow
  • Very easy to use
  • Lasts for years


Price can get quite prohibitive

Nature’s Head Dry Composting Toilet (Standard Crank Handle)

Nature's Head Dry Composting Toilet with Standard Crank Handle
Nature’s Head Dry Composting Toilet -Standard Crank (Image: Amazon)

If you want to prioritize convenience in your composting toilet, Nature’s Head Dry Composting Toilet is a product you should consider.

Made for application where water access can be limited, this composting toilet is not only eco-friendly but also very durable and portable. You don’t need to install it so you can use it just about anywhere, giving you peace of mind and comfort wherever you may go.

The biggest draw of this product is its dry composting design. It separates liquid and solid waste so decomposition can be faster and odor-free. Leaks are also prevented by this design, making it a completely hygienic and sanitary option.

Topped with a comfortable seat and you’ve got a solid option for the best composting toilet for your small home, RV, truck, or boat.

To guarantee effective waste degradation, this product is equipped with a hand crank for mixing solid waste and peat moss which provides effective odor elimination. It also has a vent pipe with a fan to release the gases.


  • Comfortable seat
  • Little to no chance of leaking
  • Sturdy and durable
  • Easy to use
  • Good height
  • Great for boats, RVs, and other similar applications


  • The handle can be hard to turn
  • A bit pricey

Sun-Mar Compact Self-Contained Composting Toilet

Sun-Mar Compact Self-Contained Composting Toilet, Model# Compact
Sun-Mar Compact Self-Contained Composting Toilet (Image: Amazon)

If installing a vent that goes all the way up to the roof won’t work for you, the Sun-Mar Compact Self-Contained Composting Toilet is the best alternative to the other Sun-Mar item on this list.

These two products share a lot of the same features except one requires electricity to run a fan, and the other can be used without such.

This electric-powered composting toilet may be a bit complicated to install, but it doesn’t mean that it can’t get the job done. It’s very important to ensure that you have properly installed the unit as it has an emergency drain that you’ll want to work properly.

Otherwise, leaks and pooling can be a problem. With the proper installation, you won’t have to worry about runoff and cleanups as this unit does a great job in turning body waste to compost.

The first composting toilet to be certified by the National Sanitation Foundation, or NSF, you can be sure that this unit is the authority in quality and engineering for such products.

It’s such a shame, however, that not every owner of this Sun-Mar item properly installs their unit, causing them some inconvenience instead. This is why it’s very important to pay close attention to the instruction manual before putting a unit in place so you can avoid all the hassles improper installation can bring.

Durable and sturdy, this Sun-Mar product is also guaranteed to last for years. Even if you use it on a daily basis at home or on weekends in your cabin, you can count on it to help you answer hundreds of nature’s calls.


  • NSF certified
  • Large capacity but a portable body
  • Odorless operation
  • Durable
  • Removable footrest


  • Installation requires some effort
  • Doesn’t separate the liquid from solid waste

Still, debating a composting toilet or a flush toilet? See the Pros & Cons of composting toilets here.

SunMar also makes a popular pre-made composting cover material, although you can make your own blend for less money (see our DIY mix here).

Composting Toilets: Buyer’s Guide

What are the benefits of using a composting toilet?

Let’s start this guide by getting you even more interested in composting toilets. If this system has piqued your interest, knowing just how beneficial it is for you might just give you more reasons to learn what these things can do. So, how can this kind of commode be beneficial for you? Here are a few ways:

Minimizes your waste production: As mentioned above, composting toilets are becoming more popular options for those who want to leave as little trace as possible on Mother Earth. As composting toilets can turn your body’s waste into something very useful, you can add one more thing to your recyclables and create less waste at the same time.

Then, there’s also the fact that you’re not contributing to the harmful waste being dumped in bodies of water. This problem is seriously plaguing aquatic ecosystems as human refuse creates marine pollution that can kill the living creatures in it.

Soil contamination can also be minimized by opting for these systems. Without pipes containing toxic waste running underground, you won’t have to disrupt soil systems and worry about the pipes getting damaged and polluting the land where it spilled.

Lowers utility costs: As some of these toilets don’t use water, you won’t have to worry about using so much water and racking up a high water bill. While you will have to get a few extras like bulking material to better manage the decomposition process, many options for these things are renewable and are also already considered waste. By opting for sawdust and coco coir, you can ensure proper decomposition of your body waste and recycle other production processes’ waste at the same time.

You also get to cut down on sewerage and plumbing maintenance costs with composting toilets. As these systems are very easy to maintain, you can expect to pay less for keeping your home in top shape.

Makes you self-sufficient: In the case of droughts and failures of established sewage systems, you won’t have to worry about human waste disposal because composting toilets will still work, even with little to no water for flushing waste down the drain.

What a composting toilet is and how it works

Those who have never heard of a composting toilet before maybe a bit confused about what it is. It’s actually pretty straightforward and the name says it all: It’s a toilet that turns your waste into compost. Instead of sending your body’s excretions down a septic tank or sewage system, it has a composting unit that processes the waste and turns it into fertilizer.

It works the same way as your garden composting system does, except it has an addition of a toilet unit where you eliminate bodily waste with ease. They often look just like a traditional toilet so you won’t have to feel like you’re roughing it out or as if you don’t live in the 21st century. The waste will then be transferred to a composting unit where the magic happens

Inside the waste container, oxygen is supplied to speed up the decomposition process through an anaerobic process. Heat is also used to help pick up the pace and make the waste’s degradation even faster. Moisture is removed through the help of a leachate system, and ventilation is provided to release the evaporation of such. The growth of specific bacteria is also encouraged to help assist in the process.

All of these assist in breaking down the waste and eliminating most of the harmful ingredients in human waste. In the end, you’ll get a high-quality fertilizer that you can use as a soil amendment for gardening and farming.

Types of composting toilets

There are a few different types of composting toilets that you can choose from. They largely differ in construction, engineering, and capacity, making them suitable for various needs. There are two general types that you need to be aware of.

Self-contained composting toilets

Again, as the name suggests, these toilets hold and process the waste and turn it into fertilizer right inside the unit. This makes them a bit bulkier than your regular toilet, but most units don’t really take up too much space to be too cumbersome for tiny bathroom spaces. They also look a lot like regular toilets, so you won’t feel weird using them.

As these units don’t have to move the waste from one spot to another, there’s no need for it to have a flushing system. To eliminate odors and speed up the waste’s decomposition, you’ll have to use bulking materials like peat moss or sawdust instead. Despite the simplicity of their design, they still have a fan to ensure an ample oxygen supply and a heater to speed up the composting.

Because of the smaller waste storage, these units will also require more frequent emptying. This makes them more suitable for limited use. Some also use additional composting barrels if they opt for these in their homes.

Central system composting toilets

Designed for more extensive use, this type of composting toilet has a separate waste tank where the composting takes place. The waste storage can be large in size it can also be placed underground or outside, giving you options when it comes to extracting the compost. This design, however, makes them in need of a flushing method, so it’s also available in two subtypes:

  • Micro-flush toilets use a small amount of water to push the waste from the toilet to the waste tank. They also require additional measures to get rid of moisture
  • Waterless toilets, as the name suggests, do not use water. Waste is sucked through a vacuum instead to move it to the composting unit. While it’s a great option for locations without limited water access, it requires the waste storage to be located under the commode, which can complicate the compost extraction later on.

Choosing between a self-contained and central system is one of the first steps you should take if you’re planning on switching to this plumbing-free arrangement. When weighing your options, you should make sure that the capacity of the waste container is proportional to the amount of waste your household can produce. Maintaining self-contained composting toilets can get tiresome if it’s used on a daily basis in a regular home, so you should consider such factors before making a decision in this particular aspect.


With the increasing interest in tiny and off-grid homes, certain home components that were once deemed to be too “hippie” are now becoming in demand. As more people see just how bad things are turning out for Mother Nature, those who are becoming more environmentally conscious are willing to take steps to help out.

Many of today’s current trends, including the use of composting toilets, can be some of the most promising ways to minimize your waste and carbon footprint. However, getting started can be quite tricky. So to help you out, here’s a quick guide to how these things work and how they can be a great fit for your home.

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