1/3 HP and 1/2 HP garbage disposals are considered entry-level for household use. They are very similar to each other, so it is not uncommon for customers to have a hard time choosing between them. It helps to know what the differences between them are to make a better buying decision.
The main difference between 1/3 HP and 1/2 HP garbage disposals is their grinding power. 1/2 HP garbage disposals are better at grinding food waste than 1/3 HP models. 1/2 HP models are also less likely to jam when compared to 1/3 HP disposals.
1/3 and 1/2 HP garbage disposals are made by all brands like Waste King, InSinkErator, GE, Whirlpool, Moen, etc, and each model is vastly different depending on its manufacturer. It is not sensible to compare a 1/2 HP model by one brand against a 1/3 HP model by another brand as most of the differences between them are the general differences between any two models by those brands. That comparison won’t help a reader trying to decide between a 1/3 and a 1/2 HP model.
If you are interested, here are some top garbage disposals in the 1/2 HP range (View them on Amazon) and some in the 1/3 HP range (View them on Amazon).
So let me make a comparison based on the grinding power of garbage disposals and some perks that come with the horsepower upgrade.
Differences between 1/3 HP and 1/2 HP Garbage Disposals
Here are some differences between a 1/3 HP and a 1/2 HP garbage disposal that may make sense to a person who struggles to choose between the two;
1/2 HP disposals can grind tougher foods
1/2 HP garbage disposals can grind ‘slightly’ tougher foods than 1/3 HP garbage disposals. I am stressing the word ‘slightly’ here because that is all the improvement a 1/2 HP motor offers. You can put items like fish bones in a 1/2 HP disposal, but you can’t do that with a 1/3 HP unit. As you know, fish bones are very light; you can basically break them with your fingers. 1/2 HP disposals cal also manage cooked meat when put in small quantities.
1/2 HP garbage disposals jam less often
1/2 HP garbage disposals jam less often than 1/3 HP disposals owing to their better grinding power. The higher horsepower adds more torque to the impeller of the disposal reducing the chances of jams.
1/2 HP disposals are suitable for those who cook often
Let me define ‘often’; once or twice a week. If you cook more frequently go for a 3/4 HP garbage disposal.
A 1/3 Hp disposal is suitable for a household of one or two people who cook once in a while. A 1/2 HP disposal is okay for the same number of people if they cool once a week.
1/3 HP garbage disposals are cheaper
1/3 HP garbage disposals are slightly cheaper when compared to 1/2 HP models. The difference in pricing is mostly due to the higher price of the motor.
1/3 HP disposals have shorter warranties
The warranty period of a garbage disposal depends on the company that makes it. Across the same brand, a 1/3 HP unit tends to have a shorter warranty when compared to a 1/2 HP model.
Similarities between 1/3 and 1/2 HP garbage disposals
Dimensions
Across the same brand, the dimensions of 1/3 and 1/2 HP garbage disposals are usually the same. This is because manufacturers use the same body for both HP of disposals. For example, Badger 1 and Badger 5 garbage disposals by InSinkErator have the same height and width even though the former is 1/3 HP and the latter is 1/2 HP. If you replace the motor of Badger 1 with a 1/2 HP motor, you get a Badger 5 disposal.
Build quality
The build quality of the grinding components and other parts of most 1/2 and 1/3 HP models across the same brand is the same. For example; the grinding components of Waste King 1001 and Waste King 111 are made of galvanized steel and their grinding chambers are made of corrosion-resistant plastic.
As 1/2 HP and 1/3 HP disposals are entry-level, their grinding components often do not have the same quality as those used in 3/4 and 1 HP disposal models. Most 1/2 and 1/3 HP garbage disposals have galvanized steel grinding components which are less durable than the stainless steel components in other models.
Lack of noise insulation and premium features
Since 1/2 and 1/3 HP disposals target budget customers, they often do not have any noise insulations to cut costs. They also do not have any premium-level features like multi-stage grinding or similar technologies.
Can I replace a 1/3 hP garbage disposal with a 1/2 hP?
You can replace a 1/3 HP garbage disposal with a 1/2 HP one as long as both models are from the same brand. All these garbage disposals use either a 3-bolt mount or an EZ mount. You can easily replace one garbage disposal with another one if it uses the same mounting system.
Best 1/3 HP garbage disposals
These are two of the most popular 1/3 HP garbage disposals;
InSinkErator Badger 1

Badger 1 uses an induction motor that runs at 1725 RPM. Its grinding components are made of galvanized steel. It uses a 3-bolt mount to connect with kitchen sinks. It is compact in size with a height of 11.5 inches and a maximum width of 6.3125 inches.
Badger1 is covered under a 1-year warranty that covers the cost of labor and materials.
Waste King L-111

Waste King 111 is a popular 1/3 HP garbage disposal. It uses a permanent magnet motor that runs at 2700 RPM. It uses an EZ-mount to connect it to the sink. Its grinding components are made of galvanized steel. L-111 has a height of 12.75 inches and a width of 5.25 inches. It is covered under a 2-year warranty.
Best 1/2 HP garbage disposals
There are the popular 1/2 HP garbage disposals;
Waste King L-2600

This 1/2 HP garbage disposal uses a 2600 RPM permanent magnet motor. It has stainless steel grinding components that are more durable against corrosion. Its grinding chamber is made of high-quality plastic that is time-tested. It comes with the standard EZ mounting all Waste King garbage disposals use so it is easy to replace one model with another. It is covered under a 5-year long warranty.
InSinkErator Badger 5

Badger 5 is a very popular garbage disposal by InSinkErator. It uses a DuraDrive induction motor that runs at 1725RPM. Its grinding components are made of galvanized steel. It uses a 3-bolt assembly like all other InSinkErator models for its installation. It is covered under a 3-year warranty.
Which garbage disposal should you choose?
I recommend choosing a 1/2 HP garbage disposal over a 1/3 HP one. There is not much difference in their pricing, and the 1/2 HP ones jam less often so it makes more sense to buy a 1/2 HP model over a 1/3 HP disposal.
That being said, there are garbage disposals of other sizes as well. You can choose from 1/3 HP, 1/2 HP, 3/4 HP and 1 HP garbage disposals. Here is a detailed guide comparing different garbage disposal sizes for further reference.
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