Fan Electricity Calculator
(Units, Cost and Savings From a Lower-Watt Fan)
Enter the fan's wattage, the number of fans, hours of use and your rate. Add a new fan's wattage and price to see the saving and payback.
From the label. A typical older induction ceiling fan draws about 75 W at top speed
From your bill, in your currency
Compare with a new fan (optional)
Rated wattage on the new fan's label, for example a BLDC model
Shows how long the saving takes to pay for it
Fan Running Cost
💡 Formula Guide
This fan electricity calculator works out the units and cost of running ceiling fans from their wattage, for one fan or a whole house. It also shows the saving and payback time if you replace them with lower-watt fans.
Units and Cost
CEEW puts a typical induction-motor ceiling fan at about 75 W at top speed. Three of them running 12 hours a day for 30 days use 75 × 3 × 12 × 30 ÷ 1,000 = 81 units, which is 648 a month or 7,776 a year at 8 per unit.
The rating is for top speed. At lower speeds a fan draws less, so treat the result as the most it would cost.
Saving From Lower-Watt Fans
| Three fans, 12 hours a day | Units per month | Cost at 8 per unit |
|---|---|---|
| 75 W fans | 81 | 648.00 |
| 30 W fans | 32.4 | 259.20 |
| Saving | 48.6 | 388.80 |
If each new fan costs 3,500, the three cost 10,500 and pay for themselves in about 27 months at that saving. Fewer hours or a cheaper electricity rate stretch the payback. The 30 W figure is an example; use the rated wattage on the label of the fan you are considering.
CEEW notes that most 5-star models now use BLDC motors and that the mandatory standard sets a 53 W minimum for improved induction fans. For coolers, use the Air Cooler Electricity Calculator.
How to Use the Fan Electricity Calculator
- Enter the fan's wattage: Use the label. An older induction ceiling fan draws about 75 W at top speed.
- Enter the number of fans and hours: Type how many fans run, for how many hours a day and days a month.
- Enter your rate: Type the price of one unit from your bill.
- Compare a new fan: Optional. Type the new fan's wattage and price to see the saving and payback.
Frequently Asked Questions
How many units does a ceiling fan use?
Divide its wattage by 1,000 for units per hour. A 75 W fan uses 0.075 units an hour, 0.9 units in 12 hours and 27 units in a 30-day month.
How much do three fans cost to run?
Three 75 W fans running 12 hours a day for 30 days use 81 units, which is 648 a month at 8 per unit.
How much does a lower-watt fan save?
Replacing three 75 W fans with 30 W fans for the same hours cuts use from 81 to 32.4 units a month, saving 388.80 a month at 8 per unit.
How long does a new fan take to pay for itself?
Divide the price of the new fans by the monthly saving. Three fans at 3,500 each, saving 388.80 a month, pay back in about 27 months.
What does India's fan star rating measure?
Service value: air delivery in cubic metres per minute for each watt. CEEW notes the mandatory standard now sets a minimum of 53 W for improved induction-motor designs, against about 75 W for a typical older fan.
Does a fan use less at low speed?
Yes. The rated wattage is for top speed, so a fan on a lower setting costs less than the calculator shows.
Formulas and worked examples checked in October 2026. Typical 75 W figure and the 53 W standard checked on CEEW's fan market blog in October 2026.