Estimate your TN bill
Bill breakdown
Tamil Nadu residential slabs & charges (FY 2025-26)
| DISCOM | Slab rates (₹/unit) | Fixed | FAC | Scheme |
|---|
Tamil Nadu's 200 free units (≤500U per bill) — built into this calculator
Tamil Nadu bills on a 2-month cycle, and since May 2026 domestic bills up to 500 units get the first 200 units free (≈100 free units per month on this monthly calculator, with the extra credit shown as a subsidy line). Cross 500 units in a bill and the free quota halves to 100 units with the upper slabs (₹8.40–₹11.55) opening up — the calculator applies whichever tier your consumption is in. There is no fixed charge on LT-Ia.
Tamil Nadu bill — quick answers
How many units are free in Tamil Nadu?
Since the May 2026 G.O., domestic bills up to 500 units per 2-month cycle get the first 200 units free (≈100 units/month here). Above 500 units per bill, the free quota drops to 100 units and the upper slabs apply.
Is there a demand charge on TN bills?
No — LT-Ia domestic connections carry no fixed or demand charge under TNERC Order 6 of 2025 (in force since 1 July 2025). The bill is energy, FAC and the free-unit credit.
Keep exploring
Tamil Nadu electricity bill calculator — how your bijli bill is built
TANGEDCO runs Tamil Nadu's grid on a bi-monthly (2-month) bill cycle, and its domestic LT-Ia tariff is famous for free units: since the May 2026 government order, bills up to 500 units per cycle get the first 200 units free, then pay ₹4.70 up to 400 and ₹6.30 up to 500. Above 500 units per bill the free quota drops back to 100 units and the steep ladder (₹8.40 / ₹9.45 / ₹10.50 / ₹11.55) opens up. There is no fixed charge on LT-Ia and ₹0.20/unit FAC completes the picture.
The calculator works in months, which is exactly half the TN cycle: ≤250 units/month keeps the doubled free quota; cross 250 and TN re-prices you like a 500+ unit bill. Enter your monthly units and the subsidy line shows the extra free units.
Example: your Tamil Nadu bill for 250 units
Take a Tamil Nadu household using 250 units in one month on TANGEDCO (domestic LT-Ia). The telescopic energy charge is 50 × ₹0 + 50 × ₹2.35 + 100 × ₹4.7 + 50 × ₹6.3 = ₹902.50. Add the fixed charge (₹0.00), FAC (₹50.00) — that gives a gross bill of ₹952.50. The state subsidy of ₹117.50 is then deducted, leaving ₹835.00 payable.
Here is the same 250 units across every DISCOM in Tamil Nadu — useful when your board's name differs from the common one:
| DISCOM | Energy | Fixed | FAC | Duty | Subsidy | Total |
|---|---|---|---|---|---|---|
| TANGEDCO (domestic LT-Ia) | ₹902.50 | ₹0.00 | ₹50.00 | ₹0.00 | −₹117.50 | ₹835.00 |
| TANGEDCO (Chennai circle) | ₹902.50 | ₹0.00 | ₹50.00 | ₹0.00 | −₹117.50 | ₹835.00 |
Tamil Nadu subsidy / free-unit scheme
Tamil Nadu's May 2026 government order makes up to 200 units free in every 2-month bill for domestic connections whose bill stays within 500 units per 2 months (≈250 units/month) — doubling the old 100-units-free limit. Bills above 500 units per cycle fall back to the older scheme: 100 units free, then ₹2.35 on 101–200, ₹4.70 on 201–400, ₹6.30 on 401–500 and the upper ladder beyond. There is no fixed charge, so the bill is energy + FAC only. The calculator applies the right tier automatically.
Tamil Nadu tariff details — live data
The table below is generated from the same data the calculator uses, so what you see here is exactly what is charged. Looking for the per-unit electricity price in The slab column IS your per-unit rate — each rate applies only to the units inside its own slab range.
| DISCOM | Slabs | Fixed charge | FAC |
|---|---|---|---|
| TANGEDCO (domestic LT-Ia) | 1–50 @ ₹0, 51–100 @ ₹2.35, 101–200 @ ₹4.7, 201–250 @ ₹6.3, 251–300 @ ₹8.4, 301–400 @ ₹9.45, 401–500 @ ₹10.5, 501–above 501 @ ₹11.55 | ₹0/month | ₹0.2/unit |
| TANGEDCO (Chennai circle) | 1–50 @ ₹0, 51–100 @ ₹2.35, 101–200 @ ₹4.7, 201–250 @ ₹6.3, 251–300 @ ₹8.4, 301–400 @ ₹9.45, 401–500 @ ₹10.5, 501–above 501 @ ₹11.55 | ₹0/month | ₹0.2/unit |
Remember: in telescopic billing each slab rate applies only to the units inside its range. Many websites multiply one rate by total units — that is wrong and overstates bills. This calculator, like your DISCOM, adds slab by slab.
4 practical ways to lower your Tamil Nadu bill
- If your 2-month bill hovers near 500 units, trimming one geyser hour can keep you inside the fully-free band.
- Crossing 500 units in a 2-month bill (≈250/month) cuts your free quota in half — the sharpest cliff on the TN bill.
- Set the AC at 25°C; two degrees less costs several hundred rupees a month in these slabs.
- Compare an EV charged at night against the petrol spend — the EV tool prints the exact delta.
Quick questions about Tamil Nadu bills
Are 200 units really free in TN?
Under the May 2026 G.O., domestic consumers billed up to 500 units per 2-month cycle get the first 200 units free (≈100 units/month on a monthly view). Consumption above 500 units per bill drops the free quota back to 100 units and opens the ₹8.40+ upper slabs.
How is the TN fixed charge charged?
LT-Ia domestic connections have no fixed charge — TNERC Order 6 of 2025 (FY 2025-26, in force since 1 July 2025) lists ₹0 — so the bill is essentially energy, FAC and the free-unit credit.
What are the paid slab rates in TN?
After the state subsidy: 101–200 units ₹2.35, 201–400 ₹4.70, 401–500 ₹6.30, 501–600 ₹8.40, 601–800 ₹9.45, 801–1000 ₹10.50, above 1000 ₹11.55 — all per 2-month bill.
Is solar net-metering available in TN?
Yes — rooftop net-metering with a feed-in line is available; 3–5 kW plants typically offset over half the bill.
Explore Tamil Nadu and beyond
Try the related tools: appliance cost, AC bill, solar savings and EV charging calculators, then cross-check your official bill line by line.