Electricity Bill Calculator

What this tool does

The Electricity Bill Calculator converts appliance wattage and daily hours into kWh, or takes units straight from your meter, and prices them using tiered slab rates or a flat rate. Add a fixed charge and tax to see the estimated bill, the cost per unit and which appliances use the most energy.

An electricity bill depends on two things: how many units (kilowatt-hours) you use, and how your utility prices them. One unit is 1,000 watts running for one hour, so a 1,500 W air conditioner running six hours a day uses about 270 units a month on its own. Many utilities, including most Indian state boards, charge in slabs where each block of units has a higher rate, so cutting usage at the top of your range saves the most.

This calculator multiplies watts × hours per day × quantity × days ÷ 1000 for each appliance, or uses the units from your meter. It then applies your tariff: either a flat rate or slabs entered as “units up to, rate”, with * for all remaining units. A fixed or standing charge and a tax or duty percentage are added on top. Tariffs vary by country, state and season, so use the numbers on your own bill or tariff order.

How to use Electricity Bill Calculator

1. Choose whether to estimate usage from appliances or enter units from your meter.
2. For appliances, list each one as name, watts, hours per day, quantity.
3. Set the number of days in the billing period.
4. Choose a slab or flat tariff and enter the slabs or rate from your utility.
5. Add the fixed charge for the period and any tax or electricity duty.
6. Read the estimated bill, units, effective cost per unit and the appliance breakdown.

Tips for better results

• Check the wattage on the appliance label; for inverter air conditioners average running power is often lower than the rated figure.
• Refrigerators cycle on and off, so 8 to 12 running hours a day is more realistic than 24.
• Replacing old bulbs with LEDs and setting the AC to 24 to 26 °C are simple ways to reduce usage.
• Compare the effective cost per unit with your slab rates to see how much the fixed charge adds.

Common use cases

• Estimating the running cost of a new air conditioner or heater.
• Checking whether a high bill matches your appliance use.
• Comparing a flat-rate and a tiered tariff offer.
• Working out the charging cost of an electric scooter or car.

Common mistakes to avoid

• Charging all units at the highest slab rate instead of block by block.
• Using watts instead of kilowatts when converting to units.
• Leaving out fixed charges, meter rent or taxes that appear on the bill.