Garbage Disposal Buying Guide: How to Choose the Right Size

Garbage disposal under kitchen sink

The Spruce / Ana Cadena

When the time comes to replace an old garbage disposal, there are a number of things to consider, from the brand to the noise level, but the most critical is choosing an appropriate size, as measured by the horsepower of the motor.

Motor Size

The single most important consideration when choosing a garbage disposal—and the one that makes the most difference in price—is the horsepower of the motor. The electric motors on residential garbage disposals typically range from 1/3 to 1 hp.

1/3 horsepower: The lowest horsepower garbage disposals available are 1/3 hp. Although they may seem like a great economical option, their utility level is quite limited. These appliances get easily jammed and usually have the cheapest internal components, which will rust out relatively quickly. This option should only be considered for very limited or temporary use, such as in a vacation home used infrequently. Costs typically range from $50 to $100.

1/2 horsepower: This is the minimum horsepower recommended for typical home use. These can usually be purchased for less than $100, so they are still an affordable option. Most units fall into a cost range of $75 to $125. These appliances are physically smaller than 3/4-hp and 1-hp units, making them good for tight spaces. A 1/2-hp disposal is a great option if you don't use the disposal all the time, and can be careful not to overfeed the appliance.

The noise level tends to be quite high for these disposals. Also, it is important to run a lot of water with these units to help all of the food waste pass through. Whenever possible, opt for a 1/2 horsepower garbage disposer with stainless steel grind components, which will make it last much longer.

3/4 horsepower: This is an ideal size that will serve most kitchens quite well. At this size, a garbage disposal has plenty of power for all those leftovers and more. Most, like the InSinkErator Compact (our favorite), can even grind problematic waste such as potato peels and celery with no problem.

With this much horsepower, a disposal is not likely to jam, and many more features can be available. Stainless steel grind components, for instance, offer a much longer life, so look for that whenever possible. Also, most disposals at this size will have more sound protection, so they can run quieter than 1/2 horsepower units. One thing to keep in mind, though, is that these appliances are physically larger than the 1/2 horsepower units, so make sure you have the room to install one under your kitchen sink. Costs for a 3/4-hp disposal typically range from $125 to $200 or more.

1 horsepower: If you feel the need to grind chicken bones, fruit rinds, coffee grounds, a 1 horsepower disposal will do the trick. Most of the 1 horsepower models are the top of the line, such as the InSinkErator's Evolution Excel. They can end up being quieter than even the 3/4 horsepower models, thanks to better insulation. All disposals at this level should have complete stainless steel in the grinding chamber, have a capacity for more waste in the chamber, and be virtually impossible to jam.

These appliances can be quite large, and you will need quite a bit of space under the sink. But these are great units, and if you have the room and the money, a 1 horsepower garbage disposal can be well worth it. The price range can be quite large—from as little as $150 for economy models to more than $300, depending on features.

Other Considerations

Although motor size is the most critical decision when it comes to choosing a garbage disposal, there are also other factors that come into play.

Brand: More than most appliances, garbage disposers tend to be dominated by a relatively small number of manufacturing brands. The most popular and well-respected brand is probably InSinkErator, Now owned by Emerson Electric, InSinkErator makes dozens of different models of different sizes and configurations; their models are available at nearly every online retailer, home improvement chain, and hardware store. Other major brands include Waste King and Sink Master, both of which are made by AMC (Anaheim Manufacturing Company). Another popular brand is Moen, the well-known maker of faucets, sinks, and other plumbing fixtures. Garbage disposals are relatively simple mechanical appliances, and you can't go wrong if you buy from one of these major manufacturers, all of which produce good-quality products.

Warranty: The typical garbage disposal lasts for 8 to 10 years, which is often longer than the manufacturer's warranty, which can range from one to 10 years. Paying more for a garbage disposal can mean that it comes with a longer warranty. But there is little mechanical difference between low-end and high-price disposals of the same horsepower. Since the average garbage disposal outlives its warranty anyway, there is not much reason to spend the extra money on a unit with a longer warranty—especially since these appliances are not very expensive.

Noise level: One distinct difference in garbage disposals is the sound-deadening features that manufacturers use. If you are bothered by the noise of a disposal, look for features like nylon-coated grinding parts, insulated mounting baffles, and other sound-deadening technology.

Power cord included: Some cheap garbage disposals come without the power cord. There's nothing wrong with this, but be aware that you'll need to buy a power cord, which can add $15 or so to the cost—unless you reuse the power cord from the old disposal.

Homes with septic tanks: Considerable disagreement exists on the question of using a garbage disposal if your home is served by a septic tank and drain field rather than a municipal sewer system. Some experts argue that it's a bad idea to use a garbage disposal with a septic system, since it introduces a considerable volume of solid waste into the septic tank, which will require frequent pumping to empty it. Other authorities (especially the manufacturers of garbage disposals) argue that a proper garbage disposal can be perfectly effective when used with a septic system. Some manufacturers offer special disposals equipped with cartridges that inject the food waste with natural microorganisms to help with the breakdown of food wastes in a septic tank. Replacement cartridges can cost as little as $15 dollars and last up to six months. In addition to helping the septic tank break down wastes, the cartridge fluid also has a citrus scent that helps with controlling the odor from the sink and drain.

Other waste disposal options: Increasing numbers of communities are offering organic garbage pickup services, where "wet" garbage is collected and transported to a large composting site. There, the organic wastes are allowed to break down into compost that can be used as fertilizer for the agriculture industry. Even if such pickup is not available, some experts argue that flushing garbage down the drain is environmentally irresponsible, since the food waste can strain the capacity of sewage disposal plants and consume lots of oxygen as they are processed. These people argue that it is better to dispose of organic garbage in ordinary household trash rather than flush it into the municipal drain system. The choice is yours, but be aware that garbage disposals are under increasing criticism for the problems they cause with municipal sewage disposal systems and septic systems. It is possible that your community or apartment building may forbid garbage disposals.