How Much Does It Cost to Run a Microwave?
About $1.96 a month — $23.54 a year — for a 1,000-watt microwave used 15 minutes a day at the 2024 average rate of $0.16/kWh. An hour of actual cooking costs $0.25; reheating a plate of leftovers costs 0.8¢. It is one of the cheapest things in your kitchen, and the reason is that you measure its use in minutes. Set your own wattage and rate below.
The number printed on the door. It is the power reaching the food, not the power drawn from the wall.
Minutes, not hours — and this is the input that decides your bill.
Common cooking-power ratings
Microwave cost per month
$1.96
12.3 kWh at $0.16/kWh — $23.54 a year, including the clock.
Per hour of cooking
$0.25
1.54 kW drawn while running
Reheat a plate of leftovers
0.8¢
2 min — the oven would cost 11.5¢
The clock, per year
$1.38
1 W around the clock — 6% of the total
1,000 W of cooking power ÷ 65% efficiency = 1,538 W drawn × 15 min a day = 11.5 kWh a month of cooking, plus 0.7kWh for the clock, × $0.16 = $1.96.
Same job, 2 minutes in the microwave against 15 in a preheated oven.
Standby (the clock)
Federal standards cap standby power, so the clock costs $1.38 a year. Unplugging it between meals saves that and nothing more.
Microwaves are labelled by cooking power under IEC 60705 — the microwave energy delivered into a standard water load — while every other appliance on this site is labelled by input power. Conversion losses in the magnetron and its power supply are assumed at 35%, within the commonly published 60–70% efficiency band. Standby caps are DOE's: 1.0 W for countertop units built from June 2016 and 0.6 W from June 2026, 2.2 W and 1.0 W for over-the-range models. Not sure of your rate? Check average rates by state.
How much electricity does a microwave use?
Monthly cost = cooking watts ÷ efficiency ÷ 1,000 × hours a month × price per kWh
A microwave has a high wattage and a tiny runtime, and runtime is what bills. It draws more power than a window air conditioner while it is running, and costs less per year than almost anything else you plug in, because it runs for minutes a day rather than hours.
Worked example (1,000 W cooking power, 15 min a day, $0.16/kWh): 1,000 ÷ 65% = 1,538 W drawn × 15 min × 30 days = 11.5 kWh of cooking, plus 0.72kWh for the clock × $0.16 = $1.96 per month.
Monthly cost by wattage and daily use
Rows are minutes of cooking a day. Columns are cooking-power ratings as printed on the door. Every cell includes 1 W of standby, and every cell is smaller than the cost of a cup of coffee.
| Use per day | 700 W | 900 W | 1,000 WMost common | 1,200 W |
|---|---|---|---|---|
| 5 min | $0.55 | $0.67 | $0.73 | $0.85 |
| 10 min | $0.98 | $1.22 | $1.35 | $1.59 |
| 15 min (typical) | $1.41 | $1.78 | $1.96 | $2.33 |
| 20 min | $1.84 | $2.33 | $2.58 | $3.07 |
| 30 min | $2.70 | $3.44 | $3.81 | $4.55 |
At the US average rate of $0.16/kWh. Multiply by your own rate divided by $0.16 to adjust, or find yours on the rates by state page. Even at triple the average rate, the most-used microwave in this table stays under $10 a month.
Why a 1,000-watt microwave draws 1,500 watts
Every other appliance on this site is labelled by the power it pulls from the wall. A microwave is not. The number on the door is its cooking power — the microwave energy that lands in the food, measured by heating a standard water load under the IEC 60705 test. Producing it is lossy work: the magnetron, its high-voltage supply, the stirrer and the cooling fan take their cut first. So the meter always reads higher than the label.
| Rating on the door | Actual draw | Per hour of cooking | Reheat a plate | Per monthat 15 min a day |
|---|---|---|---|---|
| 600 WSmall compact / dorm models | 923 W | $0.15 | 3.3 min0.8¢ | $1.22 |
| 700 WCommon budget countertop | 1,077 W | $0.17 | 2.9 min0.8¢ | $1.41 |
| 900 WMid-size countertop | 1,385 W | $0.22 | 2.2 min0.8¢ | $1.78 |
| 1,000 WThe most common full-size rating | 1,538 W | $0.25 | 2.0 min0.8¢ | $1.96 |
| 1,100 WLarge countertop | 1,692 W | $0.27 | 1.8 min0.8¢ | $2.15 |
| 1,200 WOver-the-range and built-in | 1,846 W | $0.30 | 1.7 min0.8¢ | $2.33 |
The reheat column scales the 2-minute plate by cooking power — a weaker microwave needs proportionally longer to put the same energy into the same food. Monthly figures instead hold your habit fixed at 15 minutes a day, plus 1 W of standby. Conversion efficiency is assumed at 65%, the midpoint of the commonly published 60–70% band; your oven is somewhere in that range rather than exactly at it.
A higher rating is not a more expensive microwave
Read the last two columns against each other. Reheating one plate costs 0.8¢ on every microwave in the table, from 600 W to 1,200 W — the weaker one simply takes 3.3 minutes where the stronger one takes 1.7. The plate needs the energy it needs. Cooking power buys you time, not money.
The monthly column rises with wattage only because it assumes you press start for the same 15 minutes either way. That is a claim about your habits, not about the machine — and if you are reheating a fixed set of meals, the stronger microwave gets you the same food for the same money, sooner.
Why our appliance page gives a different number
Our microwave appliance page runs the standard watts-times-hours calculation on 1,200 W, treating that as the draw. If the 1,200 on your door is a cooking-power rating — and on most doors it is — the real draw is nearer 1,846 W. This page starts from the label and converts, which is why its numbers run higher. Both are small; the difference is a few dollars a year.
Microwave vs. oven energy cost
An electric oven draws 2,500 W against the microwave's 1,538 W — only about 1.6 times as much. If wattage decided the bill, the oven would be a mild extravagance. It is not the wattage. It is that the oven spends its energy heating a steel box and the air in it, holds that heat for the length of the cook, and takes several times longer to do the same job. The microwave heats the food and nothing else.
| Job | Microwave | Cost | Electric oven | Cost | Energy saved |
|---|---|---|---|---|---|
| Reheat two slices of pizza | 1 min0.026 kWh | 0.4¢ | 10 min0.65 kWh | 10.3¢ | 96% |
| Reheat a plate of leftovers | 2 min0.051 kWh | 0.8¢ | 15 min0.72 kWh | 11.5¢ | 93% |
| Cook frozen vegetables | 4 min0.103 kWh | 1.6¢ | 20 min0.79 kWh | 12.7¢ | 87% |
| Heat a frozen entrée | 5 min0.128 kWh | 2.1¢ | 30 min0.94 kWh | 15.0¢ | 86% |
| Bake a potato | 6 min0.154 kWh | 2.5¢ | 45 min1.16 kWh | 18.5¢ | 87% |
Oven energy is a 12-minute preheat at the full 2,500 W, then the element cycling at an assumed 35% duty to hold temperature. Cooking times are typical rather than measured — but the ratio between them, not their exact values, is what drives the result.
The preheat alone costs more than the whole microwave job
Bringing an empty oven up to temperature takes about 0.50 kWh, or 8.0¢ — and that is before any food goes in. The microwave reheats the entire plate on 0.051 kWh, so you spend nearly 10times the microwave's total energy just getting the oven warm. This is why the oven's disadvantage is worst on small, short jobs and narrows on a long roast, where the preheat is amortised over an hour of cooking and several servings.
Where a toaster oven and air fryer land
Between the two, and for the same reason: a smaller cavity is less mass and less air to heat, so the fixed cost of getting hot is lower. They can also brown and crisp, which a microwave cannot do at all. If the choice is between a full-size oven and a countertop one for a small meal, the countertop one wins — see the toaster oven and air fryer cost pages. If the job is simply making food hot again, nothing beats the microwave.
Does the clock cost anything?
A microwave is a famous example in every list of vampire appliances: it cooks for 15 minutes and displays the time for the rest of the day. The arithmetic does not support the outrage. Standby power on microwaves has been federally capped since 2016, and at those caps the clock is a rounding error.
| Standby power | Applies to | kWh a year | Cost a year | Share of the total |
|---|---|---|---|---|
| 0.6 W | Countertop, built June 2026 or later | 5.2 | $0.83 | 4% |
| 1.0 W | Countertop, built 2016–2026 | 8.6 | $1.38 | 6% |
| 2.2 W | Over-the-range or built-in, 2016–2026 | 19.0 | $3.04 | 12% |
Caps are DOE's energy conservation standards for microwave ovens: 1.0 W for countertop and microwave-only models built from June 2016 and 0.6 W from June 2026, 2.2 W and 1.0 W respectively for built-in and over-the-range models. Units built before June 2016 were not covered and can draw more. Share of total assumes 15 minutes of cooking a day.
Unplugging it saves $1.38 a year
At 1 W the clock costs 11.5¢ a month and accounts for 6% of what the microwave costs you. For standby to overtake cooking, you would have to use the microwave less than 0.9 minutes a day — about one reheated cup of coffee. The vampire loads worth hunting are the ones with big always-on draws, not the ones with a display; our guide to phantom power names the ones that are actually worth a power strip.
How to cut your microwave cost (and why you should not bother)
At $23.54 a year, a microwave is not where your money is going. The useful move is not to run the microwave less — it is to use it instead of the oven, and then to go look at the appliances that run for hours.
Reheat in it, do not bake in the oven
Every plate you reheat in the microwave rather than the oven saves about 10.7¢. Do it once a day and that is $38.98 a year — more than the microwave costs to run in the first place.
Skip the preheat you do not need
0.50 kWh goes into an empty oven before the food arrives. Reheating and casseroles do not need a preheated cavity; only baking, where the rise depends on hitting temperature immediately, actually does.
Do not defrost with the magnetron
Defrost mode runs the microwave at reduced power for a long stretch, which is the one way to make it use meaningful energy — and moving food from the freezer to the fridge the night before costs nothing and defrosts it more evenly.
Then go look at the real drains
Your water heater, refrigerator and heating each cost more in a month than the microwave does in a year. Put them side by side on the comparison tool, or read the 10 appliances quietly costing you the most.
Related Guides
Compare Appliance Costs
Put the microwave next to the oven and the water heater
10 Appliances Quietly Costing You the Most
The microwave is nowhere on this list
How to Save on Energy Bills
Practical tips by room with savings
Cost to Run a Toaster Oven
When you need browning the microwave cannot give you
Cost to Run an Air Fryer
The other small-cavity alternative to the oven
Electricity Rates by State
Find your state's average rate
Frequently Asked Questions
How much electricity does a microwave use per hour?
A 1,000-watt microwave draws about 1,538 watts from the wall, so a full hour of cooking uses about 1.54 kWh — roughly $0.25 at the US average rate of $0.16/kWh. The catch is that nobody runs a microwave for an hour. The typical household uses one for about 15 minutes a day, so that hourly figure is a unit of measurement rather than a bill you will ever see.
How much electricity does a microwave use per month?
About 12.3 kWh a month, or $1.96, for a 1,000-watt microwave used 15 minutes a day at $0.16/kWh. That is $23.54 a year. Of the monthly total, 11.5 kWh is cooking and 0.72 kWh is the clock sitting in standby. Double your cooking time and you add about $1.85 a month.
Is a 1,000-watt microwave really 1,000 watts?
No. The wattage printed on a microwave is its cooking power — the microwave energy delivered into the food, measured against a standard water load under IEC 60705. Getting that power out of the magnetron costs more going in: at an assumed 65% conversion efficiency, a 1,000-watt microwave pulls about 1,538 watts off your meter. Microwaves are the one kitchen appliance labelled by output rather than input, which is why a wattage-times-hours estimate that uses the door rating comes out roughly a third too low.
Is it cheaper to use a microwave or an oven?
The microwave, and it is not close. Reheating a plate of leftovers takes 2 minutes and costs 0.8¢ in a microwave; the same plate in an electric oven takes 15 minutes plus a preheat and costs 11.5¢ — about 14 times as much. The reason is not wattage: an oven draws only about 1.6 times what a microwave draws. It is that the oven spends its energy heating a steel box and the air inside it, then holds that heat for as long as the food is in there, while a microwave puts energy into the food and nothing else.
Does leaving a microwave plugged in cost money?
About $1.38 a year, which is almost certainly not worth unplugging for. The Department of Energy caps microwave standby power: 1.0 W for countertop models built since June 2016, falling to 0.6 W for those built from June 2026, and 2.2 W for over-the-range units. The clock is only 6% of what a microwave costs you. For standby to overtake cooking you would have to run the microwave less than 0.9 minutes a day.
How much does it cost to run a microwave for 5 minutes?
2.1¢ at the US average rate — five minutes of a 1,000-watt microwave is about 0.13 kWh. A one-minute reheat costs 0.4¢. You would need to run the microwave for more than an hour, in a single day, before it cost you a quarter.