About the Electricity Bill Calculator
Many utilities charge for electricity in steps: the first block of units is cheap, the next block costs more, and so on. This calculator takes the units you used, or two meter readings, and applies the steps you type in from your own tariff. It then adds a fixed monthly charge, an optional extra per unit such as a fuel adjustment, and tax or duty, and shows each step's cost and the total. Because tariffs differ by country, provider and customer type, the rates are yours to enter. The example steps are placeholders, not a real tariff.
Updated October 2026
How to use the Electricity Bill Calculator
- 1Choose Units used, or Meter readings if you have the old and new numbers.
- 2Enter the kWh used or the two readings.
- 3Type your tariff steps from the bill: how many units in each step and the price per unit. Leave the units empty on the last step for all remaining units.
- 4Add the fixed charge, any extra per unit and the tax percentage.
- 5Read the estimated bill, the cost of each step and the average price per unit.
How a slab electricity bill works
With a tiered tariff, each unit is charged at the rate of the step it falls into. If the first 100 units cost 3 each and the next 100 cost 5 each, then 150 units cost 100 × 3 plus 50 × 5, which is 550. Only the units above a step boundary pay the higher rate, not the whole consumption.
A unit on your bill is one kilowatt-hour, the energy of a 1,000 W appliance running for an hour. A 100 W bulb used for ten hours is one unit. You can find your units on the bill, or take them from two meter readings.
Reading your own bill
- Energy charge: the steps above. Copy the unit blocks and prices from the tariff on your bill or your provider's website.
- Fixed or demand charge: a set amount each month, whatever you use.
- Extra per unit: fuel cost adjustment or similar surcharges that scale with units.
- Tax or duty: a percentage added on top. This tool applies it to the energy charge, the extra and the fixed charge together.
- Other items, such as meter rent, arrears or late fees, are not included. Add them to the fixed charge if you want them counted.
Using it to plan and save
Try different unit numbers to see where the next step starts. If you are at 195 units and the next step costs much more, a small cut in usage can save more than its share. The average price per unit tells you what your last kilowatt-hours really cost.
Bills are often for two months at once. If the steps on your bill are for a month, check whether your provider doubles the step sizes, and enter the ones that match your billing period. To check what a single appliance adds to a bill, use Electricity Cost Calculator, then compare the sum with your bill here. To plan an appliance, use the Watts, Amps and Volts Calculator, and for the tax on the bill the VAT Calculator.
Features
- Units or meter readings
- Any number of tariff steps, or a flat rate
- Fixed charge, per-unit extra and tax
- Cost of each step shown
- Average price per unit
- Currency symbol picker with Indian digit grouping for ₹
Frequently asked questions
How do I calculate my electricity bill from units?
Split the units across your tariff steps and multiply each part by its price, then add the fixed charge, extras and tax. Type the steps in and the tool does it for you.
How do I get units from meter readings?
Subtract the previous reading from the current one. Choose Meter readings and enter both numbers to see the units and the bill.
Does this include my country's actual tariff?
No. Tariffs vary too much and change often, so you enter the steps from your own bill. The steps shown when the page opens are just an example.
What does leaving the last step's units empty mean?
It means all remaining units are charged at that price. It is how most tariffs end, for example “above 200 units”.
Why is my real bill different?
Bills can include arrears, meter rent, late fees, subsidies or taxes that work differently from the simple percentage used here. Treat the result as an estimate and compare it with the bill.
What if I use more units than my steps cover?
Units beyond the last numbered step are charged at the price of that last step, and the table shows it as an extra line.
How is one unit defined?
One unit is one kilowatt-hour (kWh), the energy used by 1,000 watts running for one hour.