Electricity Bill Calculator
Estimate the cost of a billing period from electricity units or two meter readings. Enter your own flat rate or progressive slab rates, then add fixed charges, an energy-charge surcharge and a one-off credit.
Inputs
Estimated electricity bill
Estimated amount for this bill
300 kWh over 30 days| Slab | kWh | Rate | Charge |
|---|---|---|---|
| All units | 300 | ₹8.00 | ₹2,400.00 |
- Energy charge
- ₹2,400.00
- Fixed charge
- ₹150.00
- Surcharge on energy
- ₹120.00
- One-off credit
- −₹0.00
| Period | kWh | Recurring cost |
|---|---|---|
| Daily average | 10 | ₹89.00 |
| 30-day month | 300 | ₹2,670.00 |
| 365-day year | 3,650 | ₹32,485.00 |
An approximation, not a utility invoice. Projections repeat this bill’s consumption and recurring charges per day; they do not reapply tariff slabs to a whole year. Subsidies, demand charges, slab-proration rules and taxes other than the entered surcharge are not modelled.
How this calculator works
Start with consumption for one bill
Subtract the previous cumulative meter reading from the current reading and multiply by the utility’s meter multiplier, if any. Use verified consumption directly if the meter was replaced, rolled over or reset. The tool rejects decreasing readings instead of inventing a rollover.
Apply a flat rate or progressive slabs
In slab mode, only the first entered number of units receives the first rate; the next entered number receives the second rate; any remaining units receive the final rate. Example slab values are not official rates for any state or provider. Tariffs that charge all units at one band’s rate are not supported by this model.
Treat projections as a run-rate
The surcharge applies only to the energy charge. Fixed charge is added afterwards and the one-off credit is subtracted last. Daily, 30-day and yearly projections use this period’s recurring cost per day, without repeating the one-off credit. Provider-specific subsidies, demand charges and slab-proration rules need a separate utility calculation.
Calculation formulas
Units = (Current reading − Previous reading) × Meter multiplierEnergy charge = Sum of units within each slab × That slab’s rateEstimated bill = Energy charge + Fixed charge + Energy-charge surcharge − CreditWorked example
Illustration: 350 units with custom slabs of first 100 at ₹4, next 200 at ₹6 and the remaining 50 at ₹8 gives ₹2,000 in energy charges. Add ₹150 fixed charge and a 5% surcharge on energy (₹100): the estimated bill is ₹2,250 before credits. All rates are illustrative.
Understanding the estimate
All prefilled powers, usage patterns and rates are editable examples. This tool runs locally in your browser. Energy-only estimates are not complete electricity bills, and comparisons are scenarios rather than guaranteed savings.
Frequently asked questions
Does this use the latest tariff for my electricity provider?
No. It contains no official tariff database. Copy your current rates and billing-period thresholds from your utility’s tariff or bill, including any applicable fixed charge and surcharge.
Why does my real bill differ?
Bills may include subsidies, fuel adjustments, taxes on different charge bases, minimum charges, demand charges, time-of-use rates and utility-specific slab rules. This calculator models only the inputs shown.
Can an entered credit exceed the bill?
Yes. If the credit is larger than energy, fixed charge and surcharge combined, the result is shown as an estimated credit balance. The yearly projection excludes this one-off credit.