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TNEB Bill Calculator (TNPDCL Domestic)

Type the units from your two-month meter reading, or the two readings themselves, and see the domestic bill TNPDCL will raise: free units, each slab's charge and the total. Add a rooftop solar size to see what the same bill looks like after solar.

Units in two monthsFree unitsBill
200200₹0
300200₹470
400200₹940
500200₹1,570
501100₹2,048
600100₹2,880
800100₹4,770

Domestic (LT-IA) consumers pay no fixed charge, so these are the full energy charges for the cycle.

Your TNPDCL Reading

Printed on your bill as consumption, or worked out from the meter card.
Enter 0 kW to see the bill without solar only.

Your Two-Month Bill

–
TNPDCL domestic bill for the cycle
Units billed–
Schedule that applies–
Free units–
Average per unit–
Solar generation in two months–
Bill after solar–
Saving per year–

The current reading must be higher than the previous reading.

Slab-by-slab working

UnitsRateCharge
What this covers: the energy charge TNPDCL bills for domestic units at the rates in force on 9 October 2026. Arrears, deposits and other adjustments on your bill are not included. To plan a rooftop system, contact a local solar contractor for the actual system size and current price.

Built and maintained by Solar Calculators Pro · The TNERC and Government orders behind these rates

How TNPDCL Works Out a Domestic Bill

Tamil Nadu bills homes once every two months, so every slab on this page is a two-month slab. TNPDCL, the distribution company that took over from TANGEDCO, reads the meter, takes the units used since the last reading and charges them telescopically: each band of units at its own rate, starting with the free units. There is no fixed charge on a domestic (LT-IA) connection.

One number decides which schedule you are on: 500 units in the cycle. At or below it, the first 200 units are free. Above it, only the first 100 units are free and the remaining bands start at ₹4.70 a unit.

Up to 500 units in two months

UnitsRate per unit
1 – 200Free
201 – 400₹4.70
401 – 500₹6.30

More than 500 units in two months

UnitsRate per unit
1 – 100Free
101 – 400₹4.70
401 – 500₹6.30
501 – 600₹8.40
601 – 800₹9.45
801 – 1,000₹10.50
Above 1,000₹11.55

These are the rates a household pays after the Government of Tamil Nadu's tariff subsidy. The free units are part of that subsidy too.

The 500-Unit Line: One Extra Unit, ₹478 More

At exactly 500 units the bill is ₹1,570: 200 free units, 200 units at ₹4.70 and 100 units at ₹6.30. Use one more unit and the whole cycle moves to the other schedule. The free allowance drops to 100 units, units 101 to 200 now cost ₹4.70 each and the 501st unit costs ₹8.40, so the bill becomes ₹2,048.40.

That jump is the most useful thing to know about a TNEB bill. If your readings hover around 500 units, a small cut in use, a five-star appliance or a modest solar system that keeps the cycle at or under 500 units is worth far more than its unit count suggests.

Below the line, the 200 free units also save money compared with the old rule. Before 10 May 2026 the first 100 units were free and units 101 to 200 cost ₹2.35, so 500 units cost ₹1,805. The same reading now costs ₹1,570, a saving of ₹235 per cycle for any home using between 200 and 500 units.

What the Tariff Order Says Versus What You Pay

The Tamil Nadu Electricity Regulatory Commission (TNERC) sets the tariff, and the state government decides how much of it to pay on behalf of households. TNERC's order effective 1 July 2025 raised tariffs by 3.16%, the inflation-linked increase allowed under its 2022 multi-year order. The government absorbed that increase for domestic consumers, so the rates households pay did not change.

Units in two monthsTNERC tariffHousehold pays
Up to 400₹4.95Free units, then ₹4.70
401 – 500₹6.65₹6.30
501 – 600₹8.80₹8.40
601 – 800₹9.95₹9.45
801 – 1,000₹11.05₹10.50
Above 1,000₹12.15₹11.55

The free units came next. The government order of 10 May 2026 raised the free allowance from 100 to 200 units for homes using up to 500 units in a cycle, and TNERC approved the extra subsidy to TNPDCL for 10 May 2026 to 31 March 2027. As of October 2026 no new domestic rate schedule has been issued for 2026-27, so the 2025-26 rates above continue.

Rooftop Solar on a TNEB Connection

With net metering, TNPDCL bills the units you draw from the grid minus the units your panels export, so the slab rules apply to a smaller number. That is where Tamil Nadu's structure becomes generous: bring the net reading down to 500 units or less and the 200 free units return.

Example, Coimbatore: a family using 620 units in two months pays ₹3,069. Coimbatore averages about 4.5 peak sun hours, so a 1 kW system makes about 216 units in a two-month cycle. The net reading falls to 404 units, inside the up-to-500 schedule, and the bill drops to about ₹965. A 2 kW system makes about 432 units, leaving 188 billed units, all of them free: the energy bill for an average cycle is ₹0, a saving of about ₹18,400 a year.

Generation is lower in the north-east monsoon months and higher in summer, so individual bills move around that average. To size a system for the whole year, use the solar system size calculator, and check the price after subsidy with the solar subsidy calculator.

Sources for These Rates

  • TNERC Suo-motu Order No. 6 of 2025 (30 June 2025): domestic tariff from 1 July 2025, ₹4.95 to ₹12.15 a unit. Listed on the TNERC tariff orders page.
  • Government of Tamil Nadu tariff subsidy, July 2025: the 3.16% increase absorbed for domestic consumers, keeping household rates at ₹4.70 to ₹11.55 with 100 free units.
  • Government of Tamil Nadu order of 10 May 2026: 200 free units for domestic consumers using up to 500 units in a two-month cycle, and TNERC's order of May 2026 approving a provisional subsidy of ₹1,545.14 crore for 10 May 2026 to 31 March 2027.
  • TNPDCL: the schedule of tariff published by the distribution company.

Rates checked on 9 October 2026. If TNERC issues a new order, the calculator above is updated to match.

TNEB Bill Questions

How many units are free on a TNEB bill now?+
From 10 May 2026, a domestic connection that uses up to 500 units in a two-month cycle gets the first 200 units free. If the cycle is above 500 units, only the first 100 units are free and the rest is charged slab by slab from ₹4.70 a unit.
Is there a fixed charge on a TNPDCL domestic bill?+
No. The domestic (LT-IA) tariff has no fixed charge, so the bill is the energy charge for the units used. Your bill can still show arrears, deposits or other adjustments, which this calculator does not include.
Why does my TNEB bill jump after 500 units?+
The whole cycle moves to the above-500 schedule. At 500 units you pay ₹1,570; at 501 units the free allowance falls to 100 units and the bill becomes ₹2,048.40. Keeping a two-month reading at or below 500 units saves about ₹478.
How do I calculate units from my TNEB meter reading?+
Subtract the previous reading from the current reading on your meter card or bill. The difference is the units used in that two-month cycle. Switch the calculator to meter readings and enter both numbers.
Why is the TNERC tariff higher than what I pay?+
TNERC's tariff from 1 July 2025 runs from ₹4.95 to ₹12.15 a unit. The Government of Tamil Nadu pays a subsidy to TNPDCL so that households pay ₹4.70 to ₹11.55 a unit, with the free units on top.
Will rooftop solar bring my TNEB bill to zero?+
Often, yes. A Coimbatore home using 620 units in two months pays ₹3,069. A 2 kW system makes about 432 units in that time, leaving 188 billed units, which fall inside the 200 free units, so the energy bill for an average cycle is ₹0.

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