How to Calculate 1 Unit of Electricity in Your Household

Many people in Pakistan don’t know how quickly electricity units add up in their homes. With rising power tariffs and fuel charges, understanding how to calculate 1 unit of electricity can help reduce monthly bills.

K-Electric, which supplies power in Karachi, calculates electricity based on kilowatt-hours (kWh). That means: 1 unit = 1 kilowatt (1,000 watts) used for 1 hour

It could be one appliance using 1,000 watts for one hour, or several smaller devices using a total of 1,000 watts for one hour.

Appliance Usage Examples

Here’s how long different home appliances take to use 1 unit of electricity:

• 12-watt LED bulb – 83 hours

• 50-watt tube light – 20 hours

• 500-watt washing machine – 2 hours

• 750-watt water pump – 1 hour and 20 minutes

• 1,000-watt electric iron – 1 hour

• 2,000-watt air conditioner – 30 minutes

• 1,200-watt inverter AC – 50 minutes

These numbers help you track and reduce your energy use.

How to Calculate Units

To calculate electricity used by any appliance, use this simple formula: Units = (Watts × Hours) ÷ 1000

Example:
A 1,200-watt inverter AC running for 2 hours: → (1,200 × 2) ÷ 1000 = 2.4 units

Why One Extra Unit Matters

K-Electric and other power providers use slab-based billing. If you cross a certain number of units, your per-unit price increases. Even one extra unit can move you to a higher billing tier.

This is why using energy-efficient appliances and being aware of usage hours can help control your bill.