Tools
TNEB / TNPDCL bill calculator 2026
Enter your bi-monthly unit consumption to estimate your bill using the current TANGEDCO domestic tariff and the revised 200 units free subsidy (effective 10 May 2026).
Uses the domestic (LT-IA) tariff under TNERC Tariff Order No. 6 of 2025 and the Tamil Nadu government's revised free-electricity subsidy effective 10 May 2026. Excludes electricity duty and any fixed/service charges — see tariff slabs and confirm against your latest bill.
Solar sizing estimate
Rough sizing only — a solar installer should account for roof area, shading, and panel wattage before you buy anything.
Inverter & battery sizing
Assumes a 0.8 power factor and a 12V battery bank at 70% usable depth of discharge — a common, conservative starting point, not a substitute for an electrician's sizing.
How your TNEB domestic bill is actually calculated
Tamil Nadu bills domestic electricity bimonthly — once every two months, on whatever your meter reads over that period, not monthly. As of 10 May 2026, the state government revised the free-electricity subsidy: if your total bimonthly consumption is 500 units or less, the first 200 units are free. Cross 500 units and the free allowance drops back to 100 units, and the remaining slabs are also priced higher. Both changes hit at once, which is why a bill can jump sharply for a household that goes from 495 units one cycle to 505 the next.
Domestic (LT-IA) telescopic slabs
| Bimonthly units | Rate (500 units or less) | Rate (above 500 units) |
|---|---|---|
| 0 – 100 | Free | Free |
| 101 – 200 | Free | ₹4.95 / unit |
| 201 – 400 | ₹4.95 / unit | ₹4.95 / unit |
| 401 – 500 | ₹6.65 / unit | ₹6.65 / unit |
| 501 – 600 | Not applicable (500 is the cap for this tier) | ₹8.80 / unit |
| 601 – 800 | Not applicable | ₹9.95 / unit |
| 801 – 1000 | Not applicable | ₹11.05 / unit |
| Above 1000 | Not applicable | ₹12.15 / unit |
Telescopic means each band is charged only on the units that fall inside it — not your whole bill at the top rate you reach. Rates per TNERC Tariff Order No. 6 of 2025; excludes electricity duty and fixed/service charges.
Two worked examples
350 units (at or under 500): the first 200 units are free. The remaining 150 units (201–350) are charged at ₹4.95, giving 150 × ₹4.95 = ₹742.50.
600 units (over 500): the free allowance drops to 100 units. The next 300 units (101–400) cost 300 × ₹4.95 = ₹1,485. The next 100 (401–500) cost 100 × ₹6.65 = ₹665. The final 100 (501–600) cost 100 × ₹8.80 = ₹880. Total: ₹3,030.
The 500-unit threshold, and why crossing it costs more than it looks
Going from 500 to 501 units doesn't just add one unit's worth of charge — it triggers two changes together. The free allowance halves from 200 units to 100, and every unit from 501 onward is priced in a steeper set of slabs than anything available under the 500-unit tier. That combination is why a household hovering near 500 units sees a disproportionate jump for what looks like a small increase in usage, and it's worth checking your reading partway through the cycle if you're close to that line.
Frequently asked questions
Is the 200 units free scheme really free, or a discount?
It's a genuine subsidy, not a discount on a bill you'd otherwise pay in full — if your bimonthly consumption is 500 units or less, the first 200 units of energy charge simply aren't billed. The Tamil Nadu government funds the subsidy directly.
Is the 200-unit benefit monthly or bimonthly?
Bimonthly. TNPDCL bills domestic consumers once every two months, and the free-unit threshold applies to that two-month total, not to each calendar month separately.
Do renters get the 200 units free subsidy?
Yes — the subsidy is tied to the domestic service connection and its bimonthly consumption, not to whether the property is owner-occupied or rented.
What if my bimonthly usage is exactly 500 units?
Exactly 500 units falls in the "500 or less" tier, so you'd still get the full 200 free units and the lower slab rates.
Does this calculator include fixed charges or electricity duty?
No — it estimates the energy charge only, using the current telescopic domestic slabs. Fixed/service charges and electricity duty vary and aren't included, so treat the result as a close estimate rather than your exact bill.