If you’re short of circuits and outlets in your kitchen, you might wonder if you can use a dishwasher and disposal on the same circuit.
You can have a dishwasher and disposal on the same circuit, but only if the circuit can handle both appliances’ total power or amperage. Normally, however, both appliances are put on separate dedicated circuits, which is especially important if they are high-power or heavy-duty.
To know whether it is safe to share the same circuits, we will first need to know the individual power requirements of the two appliances.
Power Requirements
A Dishwasher’s Power Requirement
A dishwasher typically consumes between 1,200 and 1,400 watts, but the wattage may range between 600 and 2,500.
If it’s a small, compact, or energy-efficient dishwasher, the power consumption will be within the lower end of this range. It will be within the upper end if it’s large, feature-rich, older, or less energy-efficient.
The main electricity-consuming component inside the dishwasher is the heater. It typically uses more than 80% of the total power consumption. The motor consumes most of the remainder, while the drain pump only consumes a small proportion.
Some dishwashers mention this breakdown in the manual.
A Garbage Disposal’s Power Requirement
The power requirement of garbage disposal is typically stated in horsepower.
Unless you have a heavy-duty type, most disposals don’t require more than one horsepower. In wattage, this typically means between 350 and 750 watts. Regarding amperage, garbage disposals draw between 4 and 8 amps, although some larger models may require up to 10 or 12 amps.
Use the table below to know the rough equivalents between horsepower, wattage, and amperage. The actual amperage may differ depending on the model. Check the label or manual for the exact power specifications.
| Horsepower | Wattage (approx.) | Amperage | Required Breaker |
| 1/3 (one-third) | ~250 watts | 4-6 amps | Ten amps |
| 1/2 (one-half) | ~370 watts | 5-7 amps | Ten amps |
| 3/4 (three quarters) | ~560 watts | 6-8 amps | 10 or 15 amps |
| 1 HP | ~750 watts | 7-10 amps | 15 amps |
| 1.5 HP | ~1,120 watts | 9-12 amps | 20 amps |
| 2 HP | ~1,500 watts | 11-15 amps | 20 amps |
For example, a 1 HP disposal will require at least a 15-amp circuit, whereas a 20-amp circuit will be necessary for a unit that draws more than 1 HP. As you can see, garbage disposals generally don’t consume so much power unless larger than a 1 HP model.
Putting a Dishwasher and Disposal on the Same Circuit
Coming back to the main consideration, i.e., whether you can put a dishwasher and disposal on the same circuit, you must calculate the total power consumption or current draw.
Once you’ve identified the exact values for each appliance, add the two to obtain the total consumption value.
You can safely share the circuit if the total is within the limit. Usually, this will only be possible if both appliances have low power consumption or are highly energy efficient.
For example, suppose you have a 1,000-watt dishwasher and a ½HP disposal unit. The total power consumption would be approximately 1,400 watts. Technically, it would be possible to share both on a 15-amp circuit.
Various other combinations are possible. The important thing is to know the total.
However, if either one or both appliances have high power consumption, putting them on a separate dedicated circuit would be safer.
Bear in mind that many appliances require a tad bit more power when starting up before they settle down to a stable level of operation.