What an Electric Composter Costs to Run

Running an electric composter once a day costs most US households roughly $3 to $6 a month in electricity. Three numbers set that cost: the kilowatt-hours one cycle uses, what you pay per kilowatt-hour, and how many cycles you run in a month.

The question usually comes up right after the sticker price. The machines sell for $400 to more than $1,000, and you want to know whether the monthly cost will quietly add to that. For electricity the answer is that it adds a little. On some models the replacement filters add more than the power does, and a cheap machine that you run often can end up costing more to run than a pricier one you run less.

Most units are dryer-grinders. They heat the scraps to about 160°F, grind them, then cool them. Nearly all the electricity goes into the heating stage. According to Mill's usage data, about a third of its cycle is a cooldown that draws very little power.

The calculation works like this:

1. Find the kWh per cycle. Across the category it runs from 0.5 to 1.5 kWh, depending on cycle length, how wet the food is, and how the machine is designed.
2. Multiply by your rate. The EIA put the average US residential rate at 18.34 cents per kWh in its June 2026 data. EnergySage had 19 cents as of August 10, 2026. State rates ranged from about 13 cents in Oklahoma and Utah to about 35 cents in California.
3. Multiply by cycles per month. A daily cycle means about 30.

Don't use the wattage printed on the label. The Airthereal Revive is rated at 500W, but it averages about 150W while running, because it adjusts its power as it senses the load.

Every figure below comes from the maker's own kWh number, multiplied by the 18.34-cent average. I did not meter these machines myself.

Airthereal Revive (R500). It uses 0.5 to 1.6 kWh per cycle depending on how full the bin is. Airthereal's own example gives $0.21 for a full cycle, but it assumes 13 cents per kWh. At 18.34 cents a full cycle costs about $0.29. Ten full cycles a month comes to about $2.90. Thirty full cycles would come to about $8.80, which is why this compact unit is only cheap if you wait for a full bin.

Mill. It averages 0.7 kWh a day over weeks of real use. Mill's own estimate is about $4 a month at 17.8 cents. At 18.34 cents it comes to about $3.85.

Lomi 1.0. The Eco-Express mode uses 0.6 kWh per cycle, and the 16-to-20-hour Grow mode uses 1.0 kWh. Run daily, that is about $3.30 a month on Eco-Express or $5.50 on Grow.

Reencle Prime. This one runs continuously instead of in cycles. It draws 60 to 80W while working and 10 to 15W while idle. Reencle estimates about 21.6 kWh a month, which is about $3.95 at 18.34 cents. One buying guide puts it at roughly $6.50 a month instead. The sources don't explain the gap, so budget for the higher figure.

Where you live moves these numbers more than which model you pick. A daily 1.0 kWh cycle costs about $3.90 a month in Oklahoma and about $10.50 in California.

Running cost gets confused with two other numbers. Mixing them up leads to the wrong purchase.

A low running cost also says nothing about what comes out of the machine. Most units dry and grind the scraps rather than compost them, and the output needs weeks more breaking down in soil. That trade-off is covered in whether one is worth buying.

Check your own rate first. It is printed on your electric bill in cents per kWh. Then ask each maker for kWh per cycle, not watts, and multiply the two by the number of times you expect to run the machine each month. Add the yearly filter cost before you compare models, because that is where two machines with similar electricity costs can differ.

Once you own one, run fewer, fuller cycles. Mill says its setting for less frequent cycles cuts energy use by about 20%, and Airthereal's cost per cycle climbs as the bin fills, so a half-empty cycle costs you most of the energy for half the scraps. If the composter still barely registers on your bill, spend that attention on the bigger draws at home. A refrigerator runs about $13 to $15 a month.

If spending any electricity on food scraps bothers you, you can start composting for free in a bin or pile instead.