House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

5 Best Composting Toilets in 2021 – Reviews & Top Picks

Nature's Head Dry Composting Toilet with Standard Crank Handle

Composting Toilet_shutterstock_osobystistComposting toilets can be a great way to do your part to help save the environment. It can also supply you with plenty of nutrient-rich soil to use in your garden and removes the need for a septic tank. However, as composting toilets increase in popularity the number of brands available steadily increases. As you will see, not all brands are created equal and it can be difficult to sort through them all to find one suitable for your home.

We’ve chosen five different models that are very popular and easy to find to review for you so you can see how each brand is similar as well as what the biggest differences are. We’ll go over the pros and cons of each and tell you about our experience with them. we’ve also included a short buyer’s guide where we take a close look at how the composting toilet works and what things are prone to go wrong with them.

Join us while we discuss size, weight, cleaning, capacity, and more to help you make an educated purchase.


A Quick Comparison of Our Favorites

Rating Image Product Details
Best Overall
Winner
Nature’s Head NH-SPH Nature’s Head NH-SPH
  • Easy to install
  • No odor
  • Huge waste capacity
  • Best Value
    Second place
    Separett Villa 9215 Separett Villa 9215
  • Venting parts included
  • Separate urine tank
  • Includes ten compostable bags
  • Premium Choice
    Third place
    Sun-Mar Excel-NE Sun-Mar Excel-NE
  • Non-electric
  • Low profile
  • Includes variable bio drum
  • Nature’s Head Dry Composting Toilet Nature’s Head Dry Composting Toilet
  • Hand crank agitator
  • Easy to install
  • Built-in fan
  • Sun-Mar Self Contained Sun-Mar Self Contained
  • ANSI/NSF certified
  • No separating liquid from solid
  • No need to pull out any flaps
  • The 5 Best Composting Toilets – Reviews 2021

    These are the five composting toilets we are going to review for you.

    1. Nature’s Head NH-SPH Composting Toilet – Best Overall

    Nature’s Head NH-SPH

    Nature’s Head NH-SPH Composting Toilet is our pick as the best overall composting toilet. It’s easy to install and only weighs 28 pounds when empty, so it’s easily transported to hunting shacks or other remote locations. It uses all stainless-steel construction and is of durable design with a max capacity of 300 pounds. It has a huge waste capacity, and you will only need to dump it after 60 to 80 uses. It has a built-in fan to help dry solids and push vapors out of the vent, so there is very little odor, and in some cases, you can even get by without the fan. The large stainless-steel crank handle is easy to turn to initiate the composting process.

    The Nature’s Head NH-SPH is one of the best composting toilets you can find, but it does get quite heavy when it’s time to change it. For many people, it will require a helping hand. It can also be hard to tell how full the urine jar is to know when to empty it.

    Pros
    • Easy to install
    • No odor
    • Huge waste capacity
    • Easy to install
    • All stainless-steel hardware
    • 28 pounds
    • 20-inches high
    • Built-in fan
    • 300-pound max capacity
    Cons
    • Gets heavy
    • Hard to see how much urine is in the jar

    2. Separett Villa 9215 Composting Toilet – Best Value

    Separett Villa 9215

    The Separett Villa 9215 Composting Toilet is our pick for the best composting toilet for tiny houses for the money. It stands 21 inches tall and weighs only 34 pounds when empty. It features a separate urine tank that helps to keep solids dry so they can correctly compost.  It has a built-in fan that helps remove odors, and it comes with all venting parts. It also comes with ten compostable bags so you can get started using your toilet immediately.

    It’s not as easy to mix the compost with the Separett Villa as our top pick, and the fan is quite noisy.

    Pros
    • The built-in fan works with AC or DC
    • Venting parts included
    • Includes ten compostable bags
    • 34 pounds
    • Separate urine tank
    • 21-inches high
    Cons
    • Noisy fan

    3. Sun-Mar Excel-NE Composting Toilet – Premium Choice

    Sun-Mar Excel-NE Composting Toilet

    The Sun-Mar Excel-NE Composting Toilet is our premium choice composting toilet. It’s not electric, so it’s perfect for off the grid setups, and the low-profile design is easy to install. It includes a variable bio drum so you can adjust it to your needs and the recessed handle makes it easy to manage once full. It’s designed for medium to high capacity use and can last several weeks before requiring a change. It uses a 4-inch vent pipe, and you can connect the fluid drain to a container or run into a French drain.

    The downside to the Sun-Mar is that it’s quite heavy at 90 pounds dry and can be difficult for some people to get into position for installation. The overflow drain valve is also positioned high and clogs on occasion. When it does, you’ll have little time to correct it before a mess begins.

    Pros
    • Non-electric
    • Low profile
    • Includes variable bio drum with recessed handle
    • Designed for medium to high capacity use
    Cons
    • 90 pounds
    • Overflows drain clogs on occasion

    4. Nature’s Head Dry Composting Toilet

    Nature's Head Dry Composting Toilet with Standard Crank Handle

    The Nature’s Head Dry Composting Toilet is an easy to install toilet that features a built-in fan and uses a 5-inch vent pipe to quickly dry and remove vapors. A hand crank agitator helps mix the peat moss in to ensure speedy composting. The molded plastic construction is durable, and the commode uses all stainless-steel hardware. It weighs only 28 pounds when empty and is easy to get into place.

    We felt that the Nature’s Head toilet was a bit heavy and awkward to dump when full, and it usually requires two people. The handle that turns the bucket’s material is also quite hard to turn, especially as the tank becomes full.

    Pros
    • Hand crank agitator
    • Easy to install
    • Molded construction
    • Five-inch vent pipe
    • Built-in fan
    • 28-pounds
    • Stainless steel hardware
    Cons
    • Heavy and awkward when full
    • Hard to turn the handle

    5. Sun-Mar CSEM-01400WB Composting Toilet

    Sun-Mar CSEM-01400WB

    The Sun-Mar CSEM-01400WB Composting Toilet is an ANSI/NSF certified composting toilet and is one of the only brands on this list with that certification. It uses gravity to separate fluids from solids, so there is no need to pull out any flaps or worry about strong flows.

    Unfortunately, there are plenty of downsides to the Sun-Mar CSEM-01400WB. To begin with, it’s extremely expensive and is one of the costliest units you can purchase. It weighs 90 pounds empty, which ties for the heaviest toilet on this list, and the plastic hardware it uses will wear out and break. Our handle broke off after several months. The fan rattles and occasionally makes a high-pitched whirring noise, and It’s also hard to clean. It uses a pull-out tray to remove liquids that sags and touches the solids. Solids and liquids are then spilled onto the floor when you pull it out.

    Pros
    • ANSI/NSF certified
    • No separating liquid from solid
    Cons
    • 90 pounds
    • Expensive
    • Messy to clean
    • Plastic hardware
    • Noisy fan

    Buyer’s Guide

    Here are some things to consider before purchasing a composting toilet.

    How Does the Composting Toilet Work?

    Most of the composting toilets on this list begin the composting work by separating the waste into liquids and solids.  The liquids are emptied or drained away while the solids remain in the tank and are dried out using a fan or heater, powered by battery or electricity. You mix the solid with a bulking material like sawdust that absorbs moisture and improves aeration, which speeds composting. When the tank is full, you empty the contents into a compost pile to finish composting for use as soil.

    What Should I Know About a Composting Toilet?

    • Some cities and boroughs may not allow the use of a composting toilet. If you intend to convert to a composting toilet to use in your home, you will need to check with your local community to make sure it’s not against regulations.
    • It doesn’t truly compost. It only begins the process. Human waste can take six months to two years to turn into compost and may require adding lime. A high-quality composting toilet begins the process and makes the solid waste much more manageable. It also removes the odors, so it’s much more convenient to use.
    • You need to be ok with yours and any other user’s waste regularly. Many people do not give this enough thought beforehand, and it can be a quick way to waste a lot of money.

    Parts of the Composting Toilet

    A composting toilet will have a place to sit and a collection tank for the waste materials. The collection tank will consist of four parts, a storage compartment, a urine separator, a ventilation shaft, and a door to extract compost.

    Collection Tank

    The collection tank is a main component of the composting toilet, and larger tanks will hold more waste material, and they will provide more time for composting to occur. Since more composting occurs, the tank is more pleasant to change when the time comes. However, larger tanks are very heavy, so you will need to make sure you can manage the weight when they are full.

    Fluid Separator

    The fluid separator catches the urine, so it does not mix with the solid waste. Some toilets will store the fluids in a bottle or compartment that you will need to empty, while others will use a drainpipe that you will need to attach to a bucket or build a French drain. If your model uses a compartment or bottle to store the fluids, you need to make sure you can see when it’s time to change them to avoid messy overflows. We tried to point out any models on our list that made it difficult to prevent overflows.

    Toilet Compost_Shutterstock_Stephen William Robinson
    Image credit: Stephen William Robinson, Shutterstock

    Extraction Door

    When it comes to dumping, some units allow you to use composting bags, which are a little easier to change, but many require you to dump the entire unit, and some can be quite clumsy. We tried to point out any models that are difficult to empty in our reviews.

    Media

    All composting toilets require some media to mix with the solid waste. You can use many media types, including Pete moss, coconut fibers, sawdust, woodchips, shredded leaves, and plenty of others. Sawdust is the most popular and inexpensive. It also works very well.

    Fan

    Most models equipped a built-in fan to help dry solid waste and push odors out of the ventilation pipe. These fans usually require 12 volts, and we recommend looking for a model that you can plug in the wall or use with a battery. In some cases, you may be able to get away without the fan if there is enough air movement and their ventilation pipes are long enough, but you will almost certainly require one in the home.

    Fans can also be a source of noise and many toilets, and they frequently wear out and need replacing. We tried to point out any noisy or flimsy brands in our reviews.

    Conclusion

    Nature’s Head NH-SPH Composting Toilet is our recommendation for most people. It’s very easy to install and weighs only 28 pounds when empty. It has a large capacity that will only require changing every 60 to 80 uses and a durable frame, making it our pick for the best overall. The Separett Villa 9215 Composting Toilet is another smart choice and our pick for the best value. It comes with everything required, including ventilation pipes and ten composting bags, enough to last you several months.

    We hope you have enjoyed reading over these reviews, and our buyer’s guide has made you more informed.  If we have helped you find a model suitable for your home or cabin, please share these five best composting toilets on Facebook and Twitter.


    Featured Image Credit: osobystist, Shutterstock

    Related posts

    OUR categories

    Project ideas

    Hand & power tools

    woodworking

    Garden

    Automotive