Tamil Nadu Electricity Bill Calculator

Tamil Nadu operates one of India's most consumer-friendly domestic electricity billing frameworks, and the 2026–27 subsidy scheme makes it even more generous for moderate consumers. Administered by TNPDCL (Tamil Nadu Power Distribution Corporation Limited) — widely known by its historical names TANGEDCO / TNEB — residential power distribution is regulated by the Tamil Nadu Electricity Regulatory Commission (TNERC) under the LT-1A domestic tariff category. Unlike most Indian states that levy mandatory fixed demand charges per kilowatt and state electricity duties, Tamil Nadu's LT-1A residential category features no fixed charges, no meter rent, and no state duty (per published reports; confirm with TNPDCL) — households pay only for energy consumed beyond the applicable free-unit threshold.

A fundamental feature of Tamil Nadu electricity billing is its bi-monthly billing cycle. TNPDCL meter readers record domestic consumption once every two months (approximately 60 days). All slab thresholds and subsidy allowances apply to this 60-day window — so a bi-monthly figure of 300 units represents an average monthly consumption of 150 units. Understanding this is essential when comparing Tamil Nadu bills to monthly-billed states.

The big story for 2026–27 is a meaningful expansion of the free-unit benefit. Under the subsidy scheme effective 10 May 2026 (per published reports; primary documents not yet reviewed; G.O. (Ms) No. 50 dated 10 May 2026, TNERC Order No. 5 of 2026 (date not yet confirmed)), households consuming up to 500 units bi-monthly receive the first 200 units completely free — doubled from the previous 100-unit entitlement. For consumption in this ≤500-unit path, TNPDCL then applies a telescopic slab structure to the remaining units:

• 0 to 200 units: ₹0.00/unit (100% free under the 2026–27 scheme)
• 201 to 400 units: ₹4.70/unit
• 401 to 500 units: ₹6.30/unit

To illustrate the practical benefit: a household using 350 units bi-monthly pays ₹705 total — 200 free units plus 150 units at ₹4.70. Under the old 100-free-unit rule, the same household would have paid ₹900. That ₹195 saving every two months adds up significantly over the year.

The 500-unit threshold effect — why your bill can jump sharply. If bi-monthly consumption crosses 500 units, the scheme reverts to the older structure where only the first 100 units are free (not 200). This cliff means a household using 501 units bi-monthly suddenly loses 100 units of free entitlement compared to one using 499 units. The exact slab rates applicable above 500 units under the current 2026–27 order have not been independently verified for this calculator; consumers in this consumption band should consult TNPDCL directly or call 1912 for the confirmed applicable rates.

What is NOT included in this standard estimate: This calculation models the published TNERC energy tariff slabs for the ≤500-unit path. Your physical TNPDCL bill may include additional non-tariff adjustments such as: past unpaid arrears, Delayed Payment Surcharge (DPS) for late settlement, one-off fees for meter testing or replacement, penalties for unauthorized load use, or temporary connection surcharges. High-tension (HT) and commercial (LT-2) consumers are governed by distinct demand-based schedules.