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What Size Garbage Disposal Do You Need: Sizing Guide

Garbage disposals come in different sizes, aka power ratings. The most common sizes are 1/3 HP, 1/2 HP, 3/4 HP, and 1 HP. For a first-time buyer, it can be challenging to choose between these different sizes. What is the right size disposal for you?

The size needed for a garbage disposal depends on the frequency of its use and the type of food wastes one wants to dispose of. For a typical home, the recommended size is 3/4 HP even though 1/2 HP is adequate. A 1 HP size garbage disposal is recommended for a large family that cooks daily.

Here is table to quickly find out the size of garbage disposal you need;

Garbage disposal sizeNo. of people in houseFrequency of cookingWhat to grind
1/3 HP1-2RarelySoft foods, fruits, and vegetables
1/2 HP1-2Once or twice a weekfish bones, soft foods, cooked meat, vegetables, etc
3/4 HP2-43-4 days a weekchicken bones, meat, vegetables, etc
1 HP2-4+DailyBeef bones, chicken bones, meat, vegetables, etc

Common sizes for garbage disposals, and what they can grind

The ‘size’ of a garbage disposal commonly refers to its horsepower rating, not its external or internal dimensions. The more power rating it has, the more it can grind. So it makes sense to think that a large family that cooks often needs large-size garbage disposal and vice versa. Let’s see what the commonly available disposal sizes are;

Like mentioned before, garbage disposals mostly come in 1/3, 1/2, 3/4, and 1 HP sizes. There are also disposal models with 5/8 HP and 1.1 HP sizes even though they are available in limited numbers and are not that popular. Normally, for a household garbage disposal, 1 HP is the maximum power rating.

1/3 HP

1/3 HP garbage disposals are entry-level disposals that are suitable for those who cook rarely. If you are a person who lives on a diet and eats healthy foods, this size is an apt choice. But don’t ever think of putting leftover pizza in it.

Even though 1/3 HP is the entry-size most plumbers wouldn’t recommend it. It is too underpowered, and it practically cannot grind any non-veg foods. Trying to grind any hard food items or adding lots of food can jam this size disposals. If you live on soft foods, vegetables, and fruits, this is a good choice, but you can get a decent 1/2 HP garbage disposal for a few bucks more.

Also, an entry-level size like this doesn’t come with any noise insulation technologies as the companies focus more on making them cheaper. If you want a quiet disposal with more features, look for a 3/4 or 1 HP disposal.

1/2 HP

Most plumbers recommend this as the entry-level size for garbage disposals. This is suitable for a household of one or two people who are not seriously into cooking. This size can handle food wastes like fish bones, cooked meat, veggies, fruits, and soft foods.

When using a 1/2 HP garbage disposal, take care to add food wastes in small amounts. While it can handle almost all disposal-friendly food wastes in a regular household, don’t expect it to grind loads of food at a time. If you had a party or a special occasion, I recommend using the trash can instead.

Like 1/3 HP size disposals, 1/2 HP garbage disposals do not have any premium features or noise insulation. But they are very popular due to their low pricing and the right grinding capabilities.

3/4 HP

This is my favorite garbage disposal size. It is not too big nor too small, it is just the right size garbage disposal for my taste.

3/4 HP garbage disposals are suitable for a family with two to four people, ideally a couple with two kids. These disposals can grind most household food wastes, including chicken bones, fruit pits, raw meat, etc., but don’t try to grind beef bones in them. Some models like Evolution Compact can grind celery and other fibrous veggies, which are not normally put in a garbage disposal, thanks to a premium feature called MultiGrind, where food wastes undergo multiple stages of grinding which makes them finer and less prone to clog.

Many 3/4 HP garbage disposal models come with noise insulations and some premium features (click here to check those). These premium ones cost much more than a 1/2 HP disposal, but there are pocket-friendly models like Waste King 3200 if you are not looking to spend much money.

1 HP

1 HP garbage disposals are the most powerful among household garbage disposals. They have bigger motors that provide ample grinding power to dispose of all sorts of household food wastes. Many models in this power range also come with impressive noise insulation technologies which muffle the sound of their large motors.

1 HP size garbage disposals are suitable for a large family and for those who cook every day. It can even grind beef bones when fed in small quantities. Some premium models are also equipped with anti-jamming technologies to reduce jams even though a 1 HP disposal rarely jams.

The importance of choosing the right size garbage disposal and why HP matters

The performance of garbage disposals increases with the increase in their horsepower rating. Disposals with higher HP motors can grind more varieties of food wastes easily. They also tend to jam less compared to smaller garbage disposals.

Choosing the right size garbage disposal will avoid clogs, jams, and even damages to the disposal itself. If you cook regularly but bought a 1/3 Hp disposal to save money, that disposal is going to jam on a daily basis. It cannot handle much food wastes at a time and don’t ever dream of grinding anything harder than a bell pepper.

This will also lead to clogs in the drain pipes. Constant jams also burn out the motor, so it will be a real surprise if the disposal survives its warranty period.

Choosing the wrong garbage disposal size will cost you in the long term, not to mention the headaches you will suffer.

Some other things to consider while deciding garbage disposal size

While performance is an important factor to look for when buying a garbage disposal, there are a few other things too you should be aware of. Here they are;

Price

The prices of garbage disposals increase with their sizes as well as the inclusion of premium features. A 3/4 HP disposal always costs more than a 1/3 HP one. But whatever power range you are opting for, there are wallet-friendly disposal models. The price depends on the brand name too. Waste King’s Garbage disposals tend to be on the cheaper side, while those by InSinkErator are on the pricey side. Large size disposals in the 3/4 to 1 HP range are available at cheap and premium pricing. The cheaper ones won’t have much noise insulation, but they will get the job done. The pricier ones are quieter, and they get the job done too.

Build quality & warranty

The build quality of garbage disposal varies within power ranges. Entry-level garbage disposals with sizes 1/3 and 1/2 HP are made of low-quality materials compared to those with 3/4 & 1 HP ratings. The entry-level disposals have galvanized steel construction, whereas the top-end models are made of stainless steel.

The build quality also reflects on the warranties given to these products. The entry-level disposals are the ones with the shortest warranties, ranging from 1 to 4-years. The warranties of high-end disposals range from 8 years to a lifetime.

Motor type

Garbage disposals are equipped with either permanent magnet motors or induction motors. Brands like Waste King use permanent magnet motors, while InSinkErayor uses induction motors. Both types of motors have their own pros and cons. Garbage disposals with permanent magnet motors run at around 2700 RPM irrespective of the motor’s horsepower rating. Those disposals with induction motors run slower, most of them at 1725 RPMs.

High-speed motors help to cut food more times in a second, and so they reduce jams. But those with induction motors are generally quieter.

Feed type

There are two types of garbage disposals based on their feed type;

  1. Continuous feed
  2. Batch feed

Continuous feed disposals are those units where food can be fed continuously, whereas, for batch feed disposals, the food scraps need to be added in batches. You can find more information on this in this article; Batch feed vs continuous feed disposals.

Batch feed models are safer since they need to be covered with a magnetic cover to operate. If you are concerned about your children’s safety, this type of garbage disposal is the best choice. However, these models are available only in 3/4 and 1 HP sizes. On the other hand, continuous feed type disposals are available in all power ratings.

What size garbage disposal will fit your sink?

Garbage disposals are universal; they will fit any sink with a standard size drain hole which is 3.5inches. But most disposals won’t fit a sink that is more than 1/2 inch thick. You can use a special extension to counter this.

While any garbage disposal will fit your sink, it is also important to consider its external dimensions. Generally, the dimensions of a garbage disposal increase with its motor size, but you can find many compact options even among 1 HP size disposals. When you choose a garbage disposal, make sure that you have enough space under the sink to install it. A rule of thumb is, the height of the space should be at least 8 inches more than the overall height of the disposal.

Which are the popular brands of garbage disposals

The brands I often recommend are Waste King, InSinkErator, and Moen, in no particular order. InSinkErator and Waste King are the leading brands in the industry. Their garbage disposals are fundamentally different, so you may find it in your interest to refer to the following articles.

The 1/3 and 1/2 HP disposals by all the above brands are very similar, but their large size disposals differ in pricing and features. The top models of InSinkErator are feature-rich and pricey, and those by Waste King are basic and cheap. Moen disposals come in between these two. The disposals by all these brands get their job done irrespective of their prices and features.

My name is Thomas Anderson, and I have worked briefly as a plumber. Even though I am currently working on a different career path I still help out my friends and family with their plumbing issues. This is a hobby blog where I share my knowledge with the audience through random articles. Through this blog, I hope to address some common questions about garbage disposals.