Solo typeLowest wattage
Microwave Electricity Cost Calculator
Thinking of buying a microwave, or wondering what the one in your kitchen is costing you? Answer three quick questions and see what it adds to your monthly bill, based on your own state's electricity rates.
1
2
3
4
Step 1 of 3
Which type of microwave?
Don't own one yet? Pick the type you're considering. You can compare all types on the result screen.
Look on the back label for "Rated Input Power" or "Power Consumption". Don't use the output power printed on the front, which is a smaller number.
Enter a value between 600 and 3000 watts.
Step 2 of 3
How do you use it?
A rough answer is fine. You can come back and change it.
Minutes a day in microwave mode
What do you mostly do?
Power levels come from the LG manual, which lists 100% for boiling, 80% for reheating and 40% for thawing. A lower level uses fewer units.
Grill or convection use
Step 3 of 3
Where do you live?
The same oven can cost twice as much in one state as another, so this matters more than you'd think.
Electricity is billed in slabs, so the units you already use decide which slab the microwave's units land in. Leave this blank and we'll assume a household using about 250 units a month.
BEE star rating (optional)
The star label is voluntary for microwaves, so plenty of ovens don't have one. If yours does, the label shows energy per cooking cycle.
Where to Find Your Wattage
Look on the back or side label for "Rated Input Power" or "Power Consumption". That's the figure your meter records. The bigger number on the front, like 900 W, is cooking power output, which is always lower.
Book Microwave Oven Repair Without Advance Charge
Kolkata, Howrah, Barasat & Barrackpore Area
Visiting fees only ₹299
Certified Technicians
Govt. Registered Company
Book Service
More Free Appliance Tools
Troubleshoot your microwave or AC, check if a dish is microwave-safe, estimate your AC bill and more. All free, no sign-up.
See All ToolsMicrowave Ovens Worth a Look
Buying or replacing? Solo ovens draw the least power, while convection models cost more per minute but can replace your oven for baking. Tap a button to compare prices.
Convection typeBake and grill
Convection Type Microwave Oven (25 L)
Convection typeLarger families
Convection Type Microwave Oven (30 L and above)
We don't sell these products. Before you buy, check the "Rated Input Power" on the spec sheet, because that's the figure that decides your running cost.
Microwave Running Cost Guide
What Does a Microwave Really Add to Your Bill?
Here's something most buyers never notice. The big "900 W" on the front of a microwave isn't the number you pay for.
That's cooking power going into your food. The electricity going into the oven is higher, usually 1200 W to 1450 W. This guide explains the gap, what it costs in rupees, and the small habits that bring the number down.
The Number on the Box vs the Number You Pay For
Every microwave label carries two power figures. Rated output power is the cooking power delivered to your food, and it's the one brands advertise. Rated input power is the electricity the oven draws from your socket, and it's the one your meter counts.
Here are the figures from the specification pages of microwave manuals in our library.
| Oven | Output (advertised) | Input (what you pay for) | Grill / convection input |
|---|---|---|---|
| 20 L solo with grill | 700 W | 1050 W | 1000 W grill |
| 20 L solo | 800 W | 1250 W | None |
| 20 L convection | 800 W | 1200 W | 1200 W both |
| 25 L convection | 900 W | 1400 W | 1950 W convection |
| 25 L convection (another brand) | 900 W | 1450 W | 2500 W convection |
| 34 L convection | 900 W | 1400 W | 2050 W both |
| Grill model | 900 W | 1300 W | 1000 W grill |
| 34 L inverter | 1200 W | 1900 W | None |
Across these ovens, the output is roughly 62% to 71% of the input. So when you compare two models, compare their input power. That's what shows up on your bill.
How Your Bill Is Actually Worked Out
A unit of electricity, also called a kilowatt-hour, is 1000 watts running for one hour. A 1250 W microwave running for a full hour at full power would use about 1.25 units. Most of us use it for minutes, not hours, which is why the monthly number is smaller than people expect.
But the rate isn't one flat number. Indian electricity bills are charged in slabs. The first set of units costs less, and the rate climbs as you use more. On top of the energy charge come fixed charges, a fuel surcharge and electricity duty.
This is why the calculator asks for the units on your last bill. Your microwave's units sit on top of everything else your home uses, so they're charged at your highest slab, not the cheapest one. It's also why the same oven costs very different amounts in different states.
Before You Buy: Picking the Right Type
Solo
Reheating, defrosting and simple cooking. Lowest input power of any type, so it's the cheapest to run. If your microwave mostly warms up dinner, this is enough.
Grill
Everything a solo does, plus a heater for browning and crisping. The grill element adds roughly 1000 W while it's on.
Convection
Adds baking. Convection mode draws the most of any mode, 1200 W to 2500 W in the manuals we checked, and bakes run for much longer than reheats. If you'll bake once a week, that's fine. If you'll never bake, you're paying for a mode you won't use.
Inverter
Inverter models hold a steady lower power instead of switching the magnetron on and off. One point worth knowing: the 34 L inverter model in our library is rated 1900 W input, the highest of any oven we have data for. Don't assume "inverter" means lower running cost. Check the label.
Also worth checking
- Capacity. The manuals we hold cover 20 L to 34 L. Bigger cavities suit family cooking; 20 L is plenty for reheating.
- Turntable size, from 245 mm to 315 mm in our manuals. Measure your largest dish before you buy.
- Space to breathe. One manual asks for about 20 cm above, 10 cm behind and 5 cm at each side.
- Your socket. One manual specifies a 10 A circuit breaker or fuse rating for the appliance.
The BEE Star Label on Microwaves
Microwave ovens have a BEE star label, but it works differently from the one on an AC, and it's voluntary, so many models don't carry one.
Instead of rating watts, BEE rates the energy used per cooking cycle, measured in watt-hours to the IEC 60705 test method.
| Star rating | Energy per cooking cycle |
|---|---|
| 5 Star | 44 Wh or less |
| 4 Star | Above 44, up to 48 Wh |
| 3 Star | Above 48, up to 52 Wh |
| 2 Star | Above 52, up to 56 Wh |
| 1 Star | Above 56, up to 60 Wh |
Any labelled oven must also hit at least 54% microwave function efficiency and draw no more than 0.6 W on standby. The label also shows the oven type, capacity, rated output power and the label period.
Now the honest part. The gap between a 1 star and a 5 star oven is about 12 to 16 Wh per cooking cycle. At two cycles a day, that's roughly ₹6 to ₹7 a month at Kolkata rates. Worth having, but your wattage, your minutes and whether you bake matter far more.
One more catch: the star only rates the microwave function. A 5 star convection oven can still cost plenty to run if you bake with it often.
The current rating table runs to 31 December 2026. If you're reading this later, check for a revised table on the BEE star label portal.
Which Power Level for Which Job
Power level changes what you pay. At 80%, the oven uses roughly four fifths of the electricity it would at 100% for the same minutes. These pairings come from the power level table in the LG manual.
| Level | Power | Best for |
|---|---|---|
| High | 100% | Boiling water |
| Medium high | 80% | All reheating |
| Medium | 60% | Baking cakes and scones |
| Defrost | 40% | All thawing |
| Low | 20% | Softening butter and cheese |
8 Habits That Lower the Bill
- Heat only what you'll eat. One portion warms faster than the whole dish.
- Cover food and stir halfway. It keeps the heat in and stops cold spots that send you back for a second round.
- Use wide, shallow dishes. Microwaves reach only about 2.5 cm into food, so deep containers stay cold in the middle.
- Pick the right power level. 80% for reheating instead of 100% cuts the units for that job by a fifth.
- Never run it empty. It wastes power and can damage the oven.
- Use microwave mode for small jobs. Convection draws far more and takes longer.
- Batch your reheating. A warm oven does the next plate faster than a cold one.
- Don't overcook. Stop a little early and let the food stand. It keeps heating by itself for a few minutes.
Maintenance That Keeps It Efficient
A neglected microwave works harder for the same plate of food. These jobs come from the care sections of the manuals and from what our technicians see in Kolkata homes.
| How often | What to do |
|---|---|
| After each use | Wipe spills from the walls, ceiling and door with a damp cloth. Burnt-on food absorbs energy meant for your dinner. |
| Weekly | Wash the glass tray and roller ring in warm soapy water, and wipe the oven floor underneath. |
| Monthly | Check the small waveguide cover on the side wall for grease or dark marks. Check the door closes with a clean click. |
| Every 6 months | Clear the vents, and check there's still about 20 cm above, 10 cm behind and 5 cm at each side. |
| Yearly | Check the door seal and hinges, and make sure the plug sits firmly in a wall socket rather than a loaded extension board. |
The cleaning and clearance steps come from the manuals. The schedule is our own suggestion for a typical kitchen.
Signs Your Microwave Is Wasting Power
A microwave rarely announces that it's becoming inefficient. It just takes longer, and you run it longer without thinking about it.
- Food takes noticeably longer than it used to. Test it: a cup of water at full power should be hot in about a minute.
- Heating is uneven, with cold patches in the middle.
- A loud hum or buzz while running.
- A burning or electrical smell.
- The MCB trips, or the display resets during cooking.
Any of these is worth checking. Our Microwave Oven Troubleshooting Tool walks you through the likely cause in a few taps.
Repair or Replace?
Small repairs like a coupler, door switch, touchpad or waveguide cover are usually worth doing. If a major part like the magnetron or control board fails in an oven that's 7 to 10 years old, and the repair costs more than about half the price of a new one, replacing it often makes more sense.
A weakening magnetron also costs you quietly every day, because the same food takes longer. Our technician will give you an honest estimate before any work starts. Book a visit if something feels off.
Frequently Asked Questions
It depends on wattage and minutes. A 1250 W solo oven used 20 minutes a day for reheating works out to about 10 units a month. A convection oven used for baking as well can be two to three times that. Use the calculator above for your own figure.
Nothing is wrong. 900 W is the cooking power reaching your food, and 1400 W is the electricity the oven draws to produce it. The difference is lost as heat in the magnetron and transformer. Across the manuals we checked, output is roughly 62% to 71% of input.
In microwave mode it's similar to other types. The difference comes from convection mode, which draws 1200 W to 2500 W in the manuals we checked and runs much longer than a reheat. If you only reheat, a convection oven costs about the same as a solo one.
Yes. At 80% power the oven uses roughly four fifths of the electricity it would at 100% for the same number of minutes. The LG manual recommends 80% for all reheating, which covers most everyday use.
The saving is small. A 5 star oven uses about 12 to 16 Wh less per cooking cycle than a 1 star one, which is roughly ₹6 to ₹7 a month at two cycles a day at Kolkata rates. Input wattage, how long you run it and whether you bake all matter more. The label is also voluntary, so many good ovens don't carry one.
A little, for the clock and display. For ovens carrying a BEE star label the standby draw is capped at 0.6 W, which works out to roughly ₹3 a month. Ovens without a label have no published figure, so we leave standby out of the estimate rather than guess.
It shouldn't on a healthy circuit. Microwaves draw a fair amount of current, so running one alongside a kettle, iron or toaster on the same line can trip the breaker. If it trips on every socket, the oven itself may have a fault and should be checked.