Appliance Electricity Cost Calculator
Work out what any appliance costs to run per day, month and year.
An electricity bill is a single number that explains nothing. This calculator breaks out any one appliance: what it draws, how many units that becomes, and what it costs per hour, day, month and year — so you can see which device is actually responsible.
Appliance and usage
Result
Fill in the fields above and your result will appear here.
What the Appliance Electricity Cost Calculator does
Electricity is billed in units, and one unit is one kilowatt-hour: a 1,000 watt appliance running for one hour. Everything else follows from that. A 1,500 watt air conditioner running eight hours a day uses twelve units, which at ₹7.50 a unit is ₹90 a day.
The complication is that many appliances do not draw their rated power continuously. A refrigerator is switched on all the time but its compressor runs perhaps a third of the time. A thermostat-controlled geyser or inverter air conditioner behaves similarly. The effective load setting handles this.
How to use this tool
- Select an appliance to load a typical wattage, then replace it with the figure from your own rating plate.
- Enter how many hours a day it actually runs. For a fridge or geyser, enter effective running hours rather than hours switched on.
- Set the months per year for seasonal appliances — an air conditioner used five months a year costs less than half of a year-round figure.
- Enter your tariff from your bill. If that rate excludes electricity duty, add the duty percentage separately.
- Adjust the effective load for cycling appliances: around 40% for a fridge, 60–75% for an inverter air conditioner.
Formula and method
Units per day = (Watts × Effective load × Quantity × Hours) ÷ 1,000
Units per month = Units per day × Days per month
Units per year = Units per month × Months per year
Effective rate = Tariff × (1 + Duty %)
Cost = Units × Effective rate
One unit (kWh) = 1,000 watts running for one hour.
Worked example
Example: a 1.5 ton AC at 1,500 W, 8 hours a day
| Units per day | 12.0 |
| Cost per day at ₹7.50 | ₹90 |
| Cost per month (30 days) | ₹2,700 |
| Cost for a 5-month summer | ₹13,500 |
At a 70% effective load — closer to how a compressor actually cycles — the same air conditioner costs about ₹1,890 a month. Which figure is right depends on your room, insulation and set temperature.
What your result means
Cost per hour is the number that changes behaviour. Knowing an air conditioner costs ₹11 an hour makes the decision about an extra hour concrete in a way a monthly total does not.
Units per month matters because tariffs are slab-based. An appliance that pushes your household above a slab boundary costs more than its own average rate suggests — the slab estimator shows the marginal cost.
The efficiency comparison is the practical output when deciding whether a five-star appliance justifies its price. Divide the price difference by the annual saving to get the payback period.
Important considerations
- Rating plates state maximum power draw. Actual consumption is usually lower, which is what the effective load setting corrects for.
- Star ratings are revised periodically, so a five-star model from several years ago may only meet a three-star standard today.
- Standby power adds up across a household — set-top boxes, chargers and televisions on standby can account for several units a month.
- Old appliances degrade. A ten-year-old air conditioner with a dirty coil can consume 20–30% more than its rating.
- Your bill also includes fixed charges, meter rent and fuel surcharge adjustments that no appliance calculation captures.
- For a whole-house estimate, run this for each major appliance and add the results, then compare with your actual bill.
Limitations of this tool
- It models one appliance at a time and does not apply slab tariffs — it uses a single flat rate.
- Effective load is your estimate. Actual duty cycle depends on ambient temperature, insulation, thermostat setting and appliance condition.
- Fixed charges, duty on fixed charges, meter rent and surcharges are not included unless you fold them into the tariff.
Frequently asked questions
How do I calculate electricity consumption of an appliance?
Multiply the wattage by the hours it runs and divide by 1,000 to get units. A 1,500 watt appliance running 8 hours uses 12 units. Multiply by your tariff for the cost.
How much does a fridge cost to run per month in India?
A 250-litre frost-free refrigerator drawing around 150 W with a 35–40% duty cycle uses roughly 40–45 units a month, which is ₹300–₹340 at ₹7.50 a unit. Older models can use twice that.
What is a unit of electricity?
One kilowatt-hour — a 1,000 watt appliance running for one hour. It is the unit your bill charges for, and every tariff slab is expressed in it.
Is an inverter AC really cheaper to run?
Usually yes, because it modulates compressor speed instead of cycling fully on and off, which lowers the effective load once the room reaches temperature. The saving is largest with long running hours — set the effective load to around 60% and compare.