TNEB bill calculator: estimate your Tamil Nadu electricity bill

Domestic (LT-IA) connections in Tamil Nadu are billed on units used in two months, in telescopic slabs: each slab's rate applies only to the units inside that slab. There is no fixed charge for domestic connections. The rates in the table are what households actually pay after the Tamil Nadu government's per-unit subsidy is taken off the rate set by the regulator (TNERC).

There are two tiers, and your total consumption decides which one applies to the whole bill:

• Up to 500 units in two months: the first 200 units are free, units 201–400 cost ₹4.70 each and units 401–500 cost ₹6.30 each.
• Above 500 units: only the first 100 units are free. Units 101–400 cost ₹4.70, and the rate then climbs through four more slabs, up to ₹11.55 per unit above 1,000 units.

Before 10 May 2026 the lower tier had 100 free units and charged ₹2.35 for units 101–200. The government raised the free allowance to 200 units for households using up to 500 units, and TNERC's Order No. 5 of 2026 records the subsidy for it.

These are the energy charges the calculator produces for typical two-month readings. A small flat with a fridge, fans and a TV often sits between 200 and 400 units; homes running one or two air conditioners through summer can cross 600 units easily.

At 400 units you pay for 200 units at ₹4.70, which comes to ₹940. At 500 units you add 100 units at ₹6.30, for ₹1,570. At 600 units you have moved to the upper tier, so only 100 units are free and the bill is ₹2,880, nearly double the 500-unit bill for 20% more power.

The tier rule applies to the whole bill, not just the extra units. At 500 units you keep 200 free units. At 501 you lose 100 of them, units 101–200 are charged at ₹4.70, and unit 501 is charged at ₹8.40. The result: ₹1,570 at 500 units becomes ₹2,048.40 at 501 units, a jump of about ₹478 for a single unit.

If your readings usually land close to 500, it pays to keep an eye on the meter in the second month of the cycle. Note the reading on the day the assessor visits, check it again around the four-week mark, and if you're already past 250 units, ease off heavy loads such as an AC, geyser or induction cooktop for the rest of the cycle.

The calculator needs the units consumed in the billing cycle, not the meter reading itself. Subtract the previous reading from the current one; both are printed on your bill and recorded on the consumer card. If you have the meter in front of you, note the kWh figure and subtract the last billed reading. The calculator also works as a general EB bill calculator for planning: try a reading with and without an extra appliance to see what it would add over two months.

The calculator covers domestic connections only. Commercial, industrial and agricultural services in Tamil Nadu are billed under different categories, so their bills won't match these figures.

Your bill is identified by the service connection (consumer) number, usually 12 digits. You can pay on TNPDCL's own quick-pay page at tnebnet.org/qwp/qpay, at a section office counter, or through any Bharat Connect (BBPS) app. On Subspace, pick Tamil Nadu's board in the electricity list, enter the consumer number, check that the fetched amount matches your estimate, and pay by UPI. For more on reading your bill and the consumer number, see paying your TNEB bill.