How it works
Most domestic tariffs are slab (block) tariffs: the first block of units is charged at one rate, the next block at a higher rate, and so on. Only the units that fall inside a slab are charged at that slab’s rate, so 320 units is not 320 times the top rate.
Enter where each slab ends and its rate, and leave the “up to” box of the last slab empty. Then add the fixed charge, any per-unit surcharge and the duty or tax percentage from your bill.
The page does not know any particular tariff. Rates change from time to time and differ by state, company and category, so always use the numbers printed on your own bill.
Formulas used
- Energy charge = Σ (units in each slab × rate of that slab)
- Subtotal = energy charge + fixed charge + units × surcharge per unit
- Duty = subtotal × duty %
- Total bill = subtotal + duty
Worked example
With the example rates and 320 units: 100 × 3.00 + 100 × 4.50 + 100 × 6.00 + 20 × 7.50 = ₹1,500 energy charge. Add ₹100 fixed and ₹64 surcharge for ₹1,664, then 5 % duty (₹83.20) for a total of ₹1,747.20, about ₹5.46 a unit.
The calculator opens with these example values, so you can compare its answer with the text above.
Frequently asked questions
How is an electricity bill calculated?
Each slab of units is multiplied by its rate and the results are added. Then the fixed charge, surcharges and duty are added.
Why does my bill differ from this result?
Tariffs include items this page does not know, such as meter rent, different rates by time of day, subsidies or rebates. Use it as an estimate.
How do I find my slab rates?
They are printed on the bill or published in the tariff order of your state electricity regulator.
How can I lower my bill?
Because higher slabs cost more per unit, cutting the units that fall in the top slab saves the most. Efficient lighting, fans and air conditioners are the usual places to start.