Your electricity bill looks like a wall of numbers, but every line traces back to one reading - the kilowatt-hour (kWh) total on your meter. Once you can convert your own meter reading into units, the rest of the bill is mostly arithmetic on published rates.
Start with the meter difference
Kilowatt-hours to units
Your meter records energy in kWh. One unit of electricity equals exactly one kWh, so the maths starts by subtracting the previous reading from the current one. A meter that moves from 5,000 to 5,450 means you used 450 units this period.
The parts of a typical bill
- Energy charge - the per-unit price multiplied by your units. Many states use slab rates where the first 100-200 units are cheaper and later units cost more.
- Fixed charge - a flat monthly amount based on your connection (sanctioned load), no matter how little you use.
- Fuel adjustment charge (FAC)/fuel surcharge - a per-unit pass-through of power purchase costs.
- Taxes and duties - a percentage on top of the energy charge.
A sample calculation
Assume 450 units, a two-slab energy rate of Rs 5 for the first 200 units and Rs 7 for the rest: (200 × 5) + (250 × 7) = 1,000 + 1,750 = Rs 2,750. Add a fixed charge of Rs 150, a fuel surcharge of 0.30 per unit (Rs 135) and 10% GST on the energy charge (Rs 275): the estimated total is about Rs 3,310. Every state prices slabs differently, so the bill calculator on this site uses the tariffs you type in and works by the same method.
Where the big savings hide
- Run heat-producing appliances in off-peak hours in states with time-of-day pricing.
- Replace old geysers, coolers and ACs with star-rated or inverter models - cooling and heating usually drive the bill.
- 1 ton of AC roughly draws 1.1-1.3 kW, so six evening hours can add over 200 units a month alone.
Example walk-through
Estimate your own bill by reading the meter twice, a day apart, and multiplying your units by the per-unit rate your power company publishes in the tariff order. That quick check catches billing surprises and makes the number on the paper bill feel trustworthy. Use the Electricity Bill Calculator to estimate the monthly charge in seconds and the Percentage Calculator when comparing tariff increases.