One electricity unit is 1 kWh, which is 1,000 watts used for one hour. So units = watts × hours ÷ 1,000. A 100 W appliance uses one unit in 10 hours, and an 80 W ceiling fan running 12 hours a day uses 0.96 units a day, or 28.8 units in 30 days.
Pick an appliance or type the watts from its rating plate, then the hours a day. The calculator gives units per hour, per day and per month, how long it takes to use one unit, and what those units cost at your slab.
Watts, kW, kWh and units
- Watt (W): how fast an appliance draws power while it runs. A ceiling fan draws about 80 W.
- Kilowatt (kW): 1,000 watts. A 1.5 ton inverter AC runs at about 1 kW on average.
- Kilowatt-hour (kWh): 1 kW used for 1 hour. This is the unit on every DISCO and K-Electric bill. "kWh to units" is one to one.
The formula is units = watts × number × hours ÷ 1,000. For days, multiply by the days in the billing month.
Examples
- 80 W fan × 12 hours = 960 Wh = 0.96 units a day; 28.8 units in 30 days.
- 12 W LED bulb: 1,000 ÷ 12 = 83 hours to use one unit.
- 1,000 W iron for half an hour a day = 0.5 units a day, 15 units a month.
- 1.5 ton inverter AC at 1,000 W average for 8 hours = 8 units a day, 240 units in 30 days.
The watts here come from the rating plate or the box. If you do not have it, the electricity usage calculator lists typical watts for fans, ACs, fridges, motors and other home appliances.
What one unit costs at each slab
The calculator prices units at the slab you choose, adding the fuel and quarterly adjustments, the FC surcharge, electricity duty and GST in the same way the bill does. Fixed charges are left out because they do not depend on units.
| Slab | Base rate per unit | With adjustments, duty and GST |
|---|---|---|
| Protected 1 to 100 units | Rs 10.54 | Rs 15.08 |
| Protected 101 to 200 units | Rs 13.01 | Rs 18.04 |
| Unprotected 1 to 100 units | Rs 22.44 | Rs 32.64 |
| Unprotected 101 to 200 units | Rs 28.91 | Rs 40.39 |
| Unprotected 201 to 300 units | Rs 33.10 | Rs 45.41 |
| Unprotected 301 to 400 units | Rs 36.46 | Rs 49.43 |
| Unprotected 401 to 500 units | Rs 38.95 | Rs 52.41 |
| Unprotected 501 to 600 units | Rs 40.22 | Rs 53.93 |
| Unprotected 601 to 700 units | Rs 41.85 | Rs 55.89 |
| Unprotected above 700 units | Rs 47.20 | Rs 62.29 |
Unprotected homes pay one slab rate on every unit, so the slab is set by your whole month's use, not by one appliance. Crossing into the next slab raises the price of every unit. The electricity bill calculator works out the full bill.
Converter or usage calculator?
This page answers one question: how many units does one appliance, or a set of the same appliance, use. To add up a whole house (fans, lights, fridge, AC, motor and UPS losses) and see the estimated bill, use the electricity usage calculator. For an AC on its own with tonnage and thermostat setting, the AC electricity cost calculator goes further.
Two checks help with a high bill. First, multiply each big appliance's watts by its real hours and compare the total with the units on the bill. Second, watch the meter for one hour with only one appliance on: the change in the reading is its units per hour.
Rating plates show the maximum power. Motors, compressors and heaters often run below it, and standby loads add a little. Treat the result as a close estimate. Tariff figures come from the data file and change when NEPRA notifies new adjustments.
Watt and unit questions
How many watts make 1 unit of electricity?
One unit is 1,000 watt-hours. That is 1,000 W for one hour, 100 W for ten hours, or 10 W for a hundred hours. Watts alone are not units: you need to know how long the appliance runs.
How many units does a fan use in a day?
A typical 80 W ceiling fan running 12 hours uses 0.96 units a day, about 29 units a month. A 35 W DC inverter fan uses 0.42 units a day for the same hours, less than half.
How do I convert kWh to units?
They are the same thing. The unit on a Pakistani electricity bill is one kilowatt-hour. If a label says an appliance uses 300 kWh a year, that is 300 units a year, or 25 a month.
How many units does a 1,000 watt appliance use in an hour?
Exactly one unit. A 2,000 W geyser element uses two units an hour and a 1,500 W kettle 1.5 units an hour. Short run times keep their monthly use low.
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Last reviewed 9 October 2026. Results are estimates; official notices always take precedence.