6 Best Composting Toilets for Tiny Homes, RVs, Boats, and More

The Best Composting Toilets
Image by Nuchylee / Canva Photos

So you’re thinking of buying one of the best composting toilets.

Congratulations! Also, have no fear: composting toilets have come a long way. In fact, modern models are simple, safe, and positively non-stinky. Even more importantly: composting toilets are an eco-friendly alternative to traditional flush toilets.

Maybe you want to reduce your water consumption, go “off-grid,” or simply reduce your impact where you can. A composting toilet supports all these noble aims, conserves valuable resources, and contributes to the environment in the form of nutrient-rich fertilizer.

So whether you’re interested in a bathroom upgrade for your RV, cabin, boat, tiny home, or regular home β€” we’ve got the scoop on which commode is the very best composting toilet for you.

Our Top Picks: Best Composting Toilets

Short on time? Here is a quick list of the top composting toilets on the market:

1. Nature’s Head Self-Contained Composting Toilet (Crank Handle)

The best composting toilet overall

Natures Head Toilet 1

Brand: Nature’s Head / Empty Frequency: Liquid (2-4 days) & Solids (2-3 weeks) / Accessories: Yes / Weight: 28 pounds / Price: πŸ’°πŸ’°

We’re not straying from the crowd with our best overall pick: Nature’s Head is far and away the most universally praised composting toilet on the market.

It’s great for small spaces, super-simple to install, low-odor, durable, extremely lightweight, easy to empty, and reliable β€” all for under $1000. We would say it blows the competition out of the water, but there’s zero water involved.

Here’s what happens when you use a Nature’s Head composting toilet:

  • The toilet separates liquid and solid wastes, and urine collects in a container.
  • Solids are directed to a container underneath the seat and mixed with a previously-added dry composting material, such as peat moss or coconut fiber. A crank on the side turns to enable aeration. At the same time, a ventilation fan dries the container and pulls away any odors.
  • Timing varies, but in approximately 2-4 weeks, it will be time to empty the solids container. The urine container requires emptying more frequently, usually every 2-4 days.

The biggest complaint about Nature’s Head is the most common complaint about composting toilets overall: people don’t love the emptying process. The specific gripe is that the urine container needs to be emptied too frequently, sometimes as often as every couple of days.

One pro tip offered by experienced users: purchase a second solid waste bin so you can allow your solid waste more time to break down before emptying. The same goes for a second urine container β€” it’s nice to have an extra on hand if you can’t immediately empty a full container and replace it.

  • Easy install
  • Low electricity use
  • Simplicity of design & comfy seat

  • Weaker fan
  • Urine reservoir needs to be changed frequently (and can overflow)

2. C-Head Basic Model Composting Toilet

The best cheap composting toilet on a budget

C-Head Toilet

Brand:Β C-Head /Β Empty Frequency:Β Liquid (2-4 days) & Solids (1-2 weeks) /Β Accessories:Β Yes /Β Weight:Β 23-28 pounds / Price: πŸ’°

Those options are out there if you want to get ultra-cheap in your quest for a self-contained dry toilet. But be advised: if you buy a portable dry toilet for under a hundred bucks, you’ll likely find yourself with a fancy poop bucket. Since we’re rounding up the best composting toilets of 2020, we’re sticking with the toilets that actually compost waste β€” or at least begin the process.

To that end, our budget pick isn’t cheap, but it is more affordable than others. The C-Head basic model features a compact and straightforward design that works well for various lifestyles and situations, including tiny houses, cabins, RVs, boats, and more.

There are also add-ons available, like wood exteriors, an external urine diverter, a “bottom exit kit” for RVs or boats, as well as marine accessories. If you want to start simple and then add more features as needed, the C-Head composting toilet provides a basic entry point.

  • Great for very small bathrooms and non-standard spaces
  • C-Head toilets are especially popular with the boating community
  • Can use standard gallon jug containers for urine collection, meaning more flexibility with storage and less money spent

  • Frequent emptying
  • Solids barely composted

3. Air Head Composting Toilet

The best composting toilet for RVs

Air Head Toilet

Brand: Air Head / Empty Frequency: Liquids (2-4 days) & Solids (2-6 weeks) / Accessories: Yes / Weight: 20 pounds / Price: πŸ’°πŸ’°πŸ’°

Air Head holds the distinction of producing the first widely available self-contained small space composting toilet. Their products also boast a nifty design feature that makes composting toilet enthusiasts very happy: you don’t have to expose the solids tank in order to empty the liquid tank. Rejoice!

All of the composting toilets we recommend are compact. Still, the Air Head unit is truly small β€” and specially designed for tiny spaces and spaces that move. For this reason, Air Head is our pick for and the best composting toilet for boats.

  • Strong fan and screens
  • Tiny size works well for tight or unusual spaces
  • Rounded waste tanks easier to access and clean

  • A bit pricey
  • Struggles in cold weather or high humidity

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

The best composting toilet for tiny homes

Natures Head Toilet 2

Brand: Nature’s Head / Empty Frequency: Liquids (2-4 days) & Solids (2-3 weeks) / Accessories: Yes / Weight: 28 pounds / Price: πŸ’°πŸ’°

Nature’s Head for the win, again! This time with one small difference: an ultra-compact “spider handle,” which is perfect for a tiny home, or anywhere else where every inch counts.

Otherwise, this model has all the same things people love about the original Nature’s Head, like a more traditional look, sturdy modular disposal system, 5-year warranty, and full-sized seat. And due to its durable composite plastic and stainless steel hardware, it’s more hygienic and less prone to cracking than other fiberglass or inferior plastic options on the market.

  • Made in the U.S.A.
  • Easy to install, durable, and dependable
  • Can be used in a wide variety of spaces, including mobile

  • Not for humid climates
  • Frequency of emptying urine container

5. Sun-Mar Excel Non-Electric Self-Contained Composting Toilet

The best composting toilet for cabins

Sun-Mar Toilet

Brand: Sun-Mar / Empty Frequency: 6 weeks to 6 months / Accessories: Yes / Weight: 50 pounds / Price: πŸ’°πŸ’°πŸ’°

When selecting a composting toilet for a cabin, you’ll want to look for a unit that handles both heavy and sporadic use that can stand up to harsher environments and weather. The Sun-Mar Excel non-electric composting toilet is one of the higher-capacity models on the market. It is one of the only NSF certified composting toilets.

It also receives more mixed reviews than any of the other toilets on our list. Sun-Mar was one of the first to enter the composting toilet market, which means it uses an older design.

This composting toilet doesn’t separate liquid and solid wastes. Instead, it relies on a “bio-drum” to tumble and compost combined wastes. In some circumstances, this technology works just fine. Still, other times the unit is prone to problems like odor or insects.

  • Easy to set up, use, and clean
  • Sits higher up and can handle higher capacities
  • Great for cabins, but also barns, cottages, camps, yurts, etc.

  • Requires a drain
  • Unit doesn’t come with a ventilation fan β€” users strongly recommend installing one
  • Some experienced urine overflow problems, clogging, broken handles, and broken footboards

6. Separett Villa 9215 Composting Toilet

The best composting toilet for off-grid use

Villa Toilet

Brand: Separett / Empty Frequency: 3-6 weeks / Accesories: Yes / Weight: 34 pounds / Price: πŸ’°πŸ’°

Well-designed, compact, durable, and convenient: the Swedish-designed Separett Villa can connect to either AC or DC power. This makes it an excellent choice for both on and off-grid use.

The Separett is known for its sleeker-looking design and more flexible options. The ventilation fan supports up to 20 feet of venting and can run off power supplied from battery, solar, or wind sources. A unique feature is a handle-less design that automatically opens the “hatch” as you sit down, and rotates the waste container as you get up from the seat. Urine can be diverted to a grey-water system or sent outside for drainage. A child seat is also available.

  • Sleek and compact design
  • Changing waste bags is quick and easy
  • Does not require any dry composting material

  • A bit large
  • Not the dry toilet to purchase if you want more thoroughly composted waste for fertilizer

What to Look for in the Best Composting Toilets

When choosing a composting toilet, take some time to identify your specific needs:

Best Composting Toilets
Image by Berger Biotechnik & Creative Commons
  • How many people will be using the toilet, and how often? Will it be mostly seasonal or continuous use?
  • Do you have an electricity hookup to operate your composting toilet?
  • Does your toilet need to be portable or tolerant of motion?
  • Do you mind sitting down to pee (some composting toilets only operate when the seat is depressed, so heads up if this is a dealbreaker)?

You’ll also needs to plan for installation, ventilation, and maintenance. Consider how often you want to empty your toilet, and how and where you need to dispose of waste.

Full Composting

If you want to fully compost your solid waste and use it as a fertilizer on your property, you should do two things.

First, check to see if that’s legal where you live. Then, make sure you have access to an established, dedicated compost pile that can take on frequent additions of non-composted waste. The full process takes at least a year.

If (like most people) you’re looking for a quicker process, you’ll need to look into where to properly dispose of solid wastes that haven’t composted fully.

As for liquids? As we’ve learned, composting toilets work by separating liquid and solid wastes. One complaint about self-contained composting toilets is the need to frequently empty a urine container. You can get around this if you choose a model that diverts your urine to a grey-water tank or drains outside your home, via a hose. But some toilets just collect urine, and you can only reroute urine in certain living situations.

What Really Happens to the Waste

Finally, a note on the term “composting.”

The truth is, compost toilet manufacturers can over-promise just how quick and easy the composting process is. If you’re using any of the toilets on our list, you’re probably going to be dealing with emptying waste that’s only partially composted (at best). It’s important to handle and/or dispose of this material safely. Some people use an RV dumping station. Others add this “humanure” waste to an established compost pile for further decomposition and eventual use as fertilizer.

But the majority of compost toilet users just bag it up and dispose of the waste in the trash and dump urine somewhere outside. It’s essential to do some research to figure out the appropriate and lawful method for your specific situation and area.

Our Process

For this guide on composting toilets, our team spent 7 hours researching the most popular options from over 10 brands and manufacturers big and small. We then read about one hundred user reviews (both positive and negative) to discover what shoppers thought about each toilet. After comparing this data, we narrowed our list down to the top 6 composting toilets on the market. You can count on this research to guide you to a mindful purchasing decision.

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