What Size Garbage Disposal Do I Need?

Last Updated:  November 3, 2020

If you have ever lived in a house without a garbage disposal or dealt with a disposal that is out of commission, you know how much of an inconvenience that can cause – especially if you are used to using one. High-quality garbage disposals not only make kitchen clean-up easier, but they also help the environment. Less food waste ends up in landfills and you aren’t left with nasty-smelling decomposing food which also emits greenhouse gases into the air. If you are looking to install a garbage disposal and make your life that much easier, there are some important guidelines to consider when deciding on the right one.

There are actually two types of garbage disposals available:

Continuous feed Garbage Disposals

Continuous feed – This is the most popular type of disposal in the US because of its convenience and easy maintenance. This unit turns on at the flip of a switch or push of a button and keeps running until you switch it off.

This allows you to continuously feed waste into the grinder for faster clean-up which makes it ideal for homes that generate a lot of food waste.

It is also cheaper and more widely available than batch feed units. However, there are some potential safety issues.

Because the drain hole is not covered, it is easy for foreign objects such as utensils to fall inside. If you reach into the chamber while it’s still running, you can be seriously injured.

Also, you typically need to run cold water while the unit is switched in order for waste to be ground properly. This causes a lot of water wastage and can also increase your monthly water bill.

Batch feed Garbage Disposals

Batch feed – This disposal does exactly as the name suggests – it grinds food waste in batches. It includes a cover or stopper for the opening of the hole.

You must fill up the grinding chamber and cover it with the stopper before the power will turn on. This saves a lot of water and energy and prevents jams.

The stopper also prevents foreign objects from falling in and also guards against small children sticking their hands down the drain. Nevertheless, there are some drawbacks – if you typically have a lot of waste to grind, this will not be very convenient for you.

Also, it can be too easy to fill the chamber with waste and grind it at a later time. This poses a potential health hazard as food starts to rot inside the chamber and emit gases.

While both types are available in all grinding powers and chamber configurations, you likely have only seen and used continuous feed units since they are the most preferred.

What Is the Right Size Garbage Disposal for Me?

When deciding on the right size garbage disposal, you need to ask yourself three questions:

To calculate how much space is available, measure the length, height, and width of the space under your sink. Depending on the grinding power, disposal units can take up quite a bit of space.

what size garbage disposal to pick

You also need to estimate how much grinding power you will require. This depends on how many people live in your home and how often they need to use it. For example, if they are often not at home, they will not need to use the unit as much. The following guidelines are typically useful for determining which size and grinding power you will need.

While your personal needs may vary, these are general suggestions based on how much garbage disposals are used on average per person.

What Are the Pros and Cons of Different Grinding Powers?

In the world of garbage disposals, size does matter.

The bigger the unit, the more grinding power it will usually have.

That said, if you have limited space under your sink, you may have to settle for a lesser power than you may initially want or need.

Keep in mind also that while you certainly don’t want to buy and install a garbage disposal that is too small since it will jam, take up a lot of water and resources and wear out quickly, it is also not recommended to buy a bigger one than you need, even if you have the available space, since you will spend more money than is necessary.

The following is a list describing each grinder motor power, advantages, and disadvantages.

1/3 HP Garbage Disposals

This motor power is the smallest and weakest power available. While this can suffice in small apartments or houses with tiny spaces, it is not recommended for frequent use for long periods of time. It is ideal as a temporary solution or for a household of 1 or 2 people who rarely use it.



While this unit is the least expensive, you do get what you pay for and will likely end up buying a replacement sooner than later thus spending more money in the long run. In addition, it does a minimal job with grinding food waste and requires a lot of water and energy. Your drain lines will clog frequently and put extra stress on the wastewater system. As a result, it is not as conducive to the environment as larger models.

1/2 HP Garbage Disposals

This size and grinding power are also ideal for small homes, apartments, or condominiums; however, you get a little more muscle since it can grind a bigger load. For a small disposal, this is the size recommended by most plumbers.



A 1/2 HP unit is decent for most households that don’t use it on a regular basis. While it is of a little better quality and power than the 1/3 HP, it still entails a lot of water and energy for grinding. You can improve the quality by choosing a unit with stainless steel grind components which offer more use over a longer period of time.

3/4 HP Garbage Disposals

This is the highest-selling motor since it works in almost all single-family homes. Additionally, it can take more of the “hard” stuff like small bones and tough fibery produce.



While more expensive, you typically get more value for money with this motor size, especially if it features stainless steel components – you should get quite a few good years out of it without frequent replacements. It does a much better job with grinding food waste than 1/3 or 1/2 HP so it is more environmentally friendly.

1 HP Garbage Disposals

If you have more than 5 people in your household and/or a lot of cooking takes place in your kitchen, this is the minimum size motor you should use. It can handle an even bigger beating than the 3/4 HP and is usually quite forgiving. This size is also perfect for business break rooms and small industrial kitchens.



This garbage disposal may be costly, but it promises efficient industrial strength. Most 1-2 HP machines are top of the line brands that do the job well. Also, they usually have features such as auto-reverse, different grinding levels, and jam sensors. Coffee grounds, chicken bones, you name it – it can take it. Make sure that all inner components are stainless steel – although they are usually standard in these size units.

Typically, the larger the disposal unit, the more quietly it runs. However, keep in mind that certain sinks can also contribute the noise levels. If you have a stainless steel sink, this can vibrate and add to the noise made by the garbage disposal. However, porcelain-enamel sinks usually insulate against this type of noise.

My Home Has a Septic Tank. What Should I Do?

what size of garbage disposal should be with a septic tank

Many garbage disposal units can also work in homes with septic tanks. Some include a special cartridge which injects microorganisms for a better breakdown of food. You can even purchase cartridges at a reasonable price. Moreover, they also have a fresh citrusy scent to help combat odors.

Once I Have Purchased My Disposal, How Do I Install It?

Once you have decided on the right size disposal, it is recommended that you thoroughly research any unit you are considering for purchase, make comparisons, and read consumer reviews.

If you are replacing an existing garbage disposal, installation should be fairly simple. However, if you want to install a new disposal where there was none previously, you need to consider a lot of factors:

Again, properly assess the space under your sink where you plan to install the garbage disposal. Allow for other factors such as where the drain opening is placed in your sink. While there may be sufficient room for a good size unit, if your drain is off-center, your unit may interfere with other installed fixtures under the sink.

size of garbage disposal for small sink

How Do I Take Proper Care of My Garbage Disposal?

Whether you are using an economical 1/3 HP or an industrial-grade 1.0 HP disposal, treat your units with care. It is vital that you read and follow all manufacturer cautions and guidelines before using your unit. Although the larger HP motors handle more intense grinding jobs than the smaller ones, even they can be subject to overfeeding and may wear out sooner if put under regular extreme abuse. Furthermore, follow safety precautions, especially if using a continuous feed disposal.

Before reaching into the sink drain, make sure the disposal is switched off. Also, keep small children away from the running unit.

Cleaner Kitchen and Better Environment

An efficient garbage disposal will not only simplify kitchen clean-up, but it can also help in cleaning the environment. Be sure to make an informed decision and weigh the pros and cons of each model and size to make your kitchen a convenient, clean, and happy place to work.