The main part of a garbage disposal is an electric motor that turns its blades to pulverize food waste. These electric motors vary in horsepower ratings across different brands and models of garbage disposals.
The size of a garbage disposal is the horsepower (HP) rating of its electric motor. This term is used to specify the power and performance levels of garbage disposals.
The common garbage disposal sizes are 1/3 HP, 1/2 HP, 3/4 HP, and 1 HP. What size you need depends on the amount of food waste your household generates daily.
- For households with 1-2 people and minimal food waste, a 1/3 HP or 1/2 HP garbage disposal should be sufficient.
- For households with 3-5 people and moderate food waste, a 3/4 HP or 1 HP garbage disposal is recommended.
- For households with more than 5 people and heavy food waste, a 1 HP or larger garbage disposal is recommended.
It’s important to note that larger garbage disposals are generally more expensive than smaller ones, so it’s a good idea to choose a size that fits your needs without overspending.
Significance of garbage disposal size
The size of a garbage disposal holds significant importance as it directly impacts its performance, efficiency, and functionality. Here are the key aspects highlighting the significance of size:
Grinding Power varies with size
The horsepower rating determines the grinding power of the disposal. A higher horsepower rating signifies a more powerful motor, enabling the disposal to grind and break down food waste more effectively.
For example, the grinding power of a 1 HP garbage disposal is significantly more than that of a 1/3 HP model. This means that a large size garbage disposal can handle versatile food wastes ranging from soft vegetables to hard bones.
Here is a quick comparison of what each horsepower size can handle;
| Garbage disposal size | What it can grind |
|---|---|
| 1/3 HP | Soft foods, fruits, and vegetables |
| 1/2 HP | fish bones, soft foods, cooked meat, vegetables, etc |
| 3/4 HP | chicken bones, meat, vegetables, etc |
| 1 HP | Beef bones, chicken bones, meat, vegetables, etc |
Jamming vs size
Garbage disposals occasionally get stuck. The frequency of these jams is significantly more for low-horsepower models. On the other hand, higher horsepower disposals can easily cut through most obstructions thanks to their extra horsepower. They can also process more volume of food waste without effort.
Durability and Longevity
Higher horsepower disposals are generally built with sturdier components and can withstand heavier loads. They are designed to handle hard food wastes and prolonged use, resulting in increased durability and longevity. In addition, higher HP garbage disposals come with longer warranties than the rest.
Noise levels vs size
Large size disposals are supposed to be noisier since they have higher horsepower motors. However, they often incorporate advanced noise reduction technologies. These features minimize noise and vibrations during operation, providing a quieter kitchen environment. Therefore, in practice, the noise from most large garbage disposals is equal to or less than that of smaller models.
Price vs horsepower
The cost of garbage disposals varies with their horsepower ratings. A 1/3 HP garbage disposal always costs less than a more powerful 1/2 HP model from the same brand. Given below is the approximate cost of different garbage disposal sizes;
| Garbage disposal size | Price range |
|---|---|
| 1/3 HP | $50 to $100 |
| 1/2 HP | $80 to $140 |
| 3/4 HP | $140 to $300 |
| 1 HP | $150 to $500 |
This means that you will be wasting money if you choose a high-horsepower unit instead of the weaker one you need.
What size to select?
Given below is a detailed comparison of the most popular sizes 1/3 HP, 1/2 HP, 3/4 HP and 1 HP to help you decide what size you need to choose.
1/3 HP: Not recommended, but if you must
1/3 HP garbage disposals are entry-level disposals suitable for those who rarely cook. 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 practically cannot grind non-veg foods. Trying to grind any hard food items or adding lots of food can easily jam these disposers. 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: Entry level size
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.
Add food waste in small amounts when using a 1/2 HP garbage disposal. 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: Most popular size
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 grinding stages, 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: Most powerful
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 that muffle their large motors’ sound.
1 HP garbage disposals suit a large family and those who cook daily. 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.
Do I need 3/4 or 1 HP garbage disposal?
3/4 HP garbage disposals are more popular than 1 HP since they offer enough grinding power and are cheap. So in most cases, a 3/4 HP is your best choice. But if you have many people in your house and you cook often, a 1 HP garbage disposal is recommended. For further info, read the differences between 3/4 and 1 HP garbage disposals.
Is 1/2 HP garbage disposal enough?
1/2 HP is an entry-level size for a garbage disposal. This size is a good choice if you are not an avid cook and do not need to grind hard food items. Compared to more powerful disposals, 1/2 HP models tend to be cheaper. So it is a good choice if you are budget conscious.
Here is a quick comparison of 1/2 HP and 3/4 HP disposals for in-depth reading.
What is the most common garbage disposal size?
The most common garbage disposal size is 3/4 HP, followed by 1/2 HP size. The 3rd common popular size is 1 HP, and the least common size is 1/3 HP.
Motor size and space constraints
Garbage disposals with large motors ie, higher horsepower tend to be bulkier. Therefore, when deciding which model to choose, you should consider how much space you have under the sink to install the garbage disposal. A rule of thumb is, the height of the space under the sink should be at least 8 inches more than the overall height of the garbage disposal you buy.
In case you want a powerful disposer, but the available space is small, look into compact models like the Evolution series by InSinkErator. They have several powerful but compact units that can fit even under deep sinks.
Large garbage disposals also have large grinding chamber capacities. Grinding chamber capacity is the volume of the grinding chamber inside it. If you want to process large amounts of food waste at a time, definitely go for a large garbage disposal.
How do Horsepower and compatibility with kitchen sinks relate?
When it comes to compatibility with kitchen sinks, the horsepower rating of garbage disposals do not matter. This is because Garbage disposals are universal; they will fit any sink with a standard-size drain hole of 3.5 inches.
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.
How do popular brands and their size choices compare?
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.
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.
