Units it uses
What is 1 unit of electricity?
One unit on your electricity bill is one kilowatt-hour (kWh): 1,000 watts running for one hour. A 100 W appliance takes ten hours to use one unit; a 2,000 W geyser takes half an hour. So 1 kWh is equal to 1 unit, and a kilowatt-hour is a unit of energy, not power.
How to convert watts to units
Multiply the watts by the hours it runs, then divide by 1,000:
Units a month = units a day × days used
A 1,500 W appliance running 6 hours a day uses 1,500 × 6 ÷ 1,000 = 9 units a day, or 270 units in a 30-day month. At ₹8 a unit that is ₹2,160 a month.
| Appliance | Hours a day | Units a day | Units a month |
|---|---|---|---|
| 9 W LED bulb | 6 | 0.05 | 1.62 |
| 75 W ceiling fan | 12 | 0.9 | 27 |
| 1,000 W iron | 0.5 | 0.5 | 15 |
| 1.5 kW (1,500 W) AC at full power | 6 | 9 | 270 |
| 2,000 W geyser | 0.5 | 1 | 30 |
kW vs kWh: the difference
kW is power: how hard something draws electricity at a moment. kWh is energy: how much it uses over time. A 3 kW solar system can produce up to 3 kW at noon, and about 12 kWh, or 12 units, over a whole day. Your sanctioned load on the bill is in kW; your usage is in kWh.
| From | To | Multiply by |
|---|---|---|
| kW | watts | 1,000 |
| watts | kW | 0.001 |
| HP | watts | 746 |
| kWh | units | 1 |
| MWh | kWh (units) | 1,000 |
| kWh | MWh | 0.001 |
Frequently asked questions
1 kW is equal to how many units?
A kW is power, so it becomes units only over time. 1 kW running for one hour uses 1 unit (1 kWh). Running for 10 hours, it uses 10 units.
1 unit is equal to how many watts?
1 unit is 1,000 watt-hours: 1,000 watts for one hour, 100 watts for ten hours or 10 watts for 100 hours.
How many units does a 1.5 ton AC use in an hour?
A 1.5 ton inverter AC is rated around 1,500 W, so at most about 1.5 units an hour. Once the room cools the compressor slows down, and a typical hour averages closer to 1 unit.
How many watts are in 1 kW?
1,000 watts. A kilowatt is a thousand watts, and a megawatt is a thousand kilowatts.
Kilowatt-hour is the unit of what?
Energy. It measures how much electricity is used or produced over time, which is why bills and solar output are counted in kWh.
Adding up a whole house? Use the home load calculator. The formulas are on how we calculate.