Kilowatt-hour (kWh)
Definition. A kilowatt-hour is the energy used by a one-kilowatt load running for one hour, and it is the unit in which every Pakistani electricity bill measures and prices consumption.
Also called: kWh · Unit · Board of Trade unit · یونٹ
Where you see it: As 'units' on the bill; as kWh on the meter display and on appliance labels.
Power versus energy
A kilowatt is a rate — how fast energy is being used at this instant. A kilowatt-hour is a quantity — how much has been used over time. The appliance label tells you the rate; the bill charges you for the quantity.
The conversion is simply watts multiplied by hours, divided by a thousand. A 2,000-watt geyser for ninety minutes is 2 × 1.5 = 3 units.
Getting a feel for the number
One unit runs a 60-watt ceiling fan for about sixteen hours, a 9-watt LED bulb for over four days, or a 1.5-ton inverter air conditioner for roughly fifty minutes.
Holding those three comparisons in your head is enough to diagnose most household bills without any calculation at all.
Where tons and horsepower fit
Air conditioners are sold in tons of cooling and pumps in horsepower, neither of which is an electrical input figure. A ton of cooling needs roughly 0.9 to 1.2 kW of input depending on efficiency; one horsepower of shaft output needs about 0.9 kW of input after motor losses.
Converting to watts before doing any bill arithmetic avoids the most common estimation error.
Frequently asked questions
Is one unit the same as one kWh?
Yes. 'Unit' on a Pakistani bill means exactly one kilowatt-hour, and the two terms are used interchangeably in tariff notifications.
What is a kVAh and why does my bill show it?
kVAh measures apparent energy including the reactive component. Demand-metered commercial and industrial connections are sometimes billed on it, which is where power factor starts to cost money.
Related terms
- Units consumed — The one number on your bill that you can actually verify yourself, how it is derived from two readings, and the arithmetic that turns it into rupees.
- kVA versus kW — Why generators and UPS units are rated in kVA but appliances in watts, and how to size equipment correctly for a Pakistani installation.
- Power factor — What causes poor power factor in a Pakistani industrial connection, how the penalty is calculated, and whether a capacitor bank pays for itself.
- Connected load — How a DISCO arrives at the connected load written on your bill, why it is always larger than what you actually draw, and when an out-of-date figure costs you money.
Go further
Back to the full 44-term glossary, or open your own bill with the reference number lookup.