How is the electricity bill calculated in India?

Residential electricity bills add four components: (1) energy charge — units consumed priced at the state's slab tariff; (2) fixed charge — a flat monthly amount per connection, varying by sanctioned load; (3) electricity duty — a state-level levy of 5-16% on the energy charge; and (4) GST — currently 0% for residential supply since electricity is exempt under §9(2) of the CGST Act. The energy charge is the largest component and is calculated telescopically — each unit is priced at the slab it falls into, not the entire bill at the top-slab rate.

What is telescopic billing?

Telescopic billing means each unit of consumption is charged at the slab rate it falls into. If a discom has slabs at 0-100 units @ ₹4 and 101-300 units @ ₹8, and you consume 200 units, you pay 100 × ₹4 + 100 × ₹8 = ₹1,200 — NOT 200 × ₹8 = ₹1,600. Almost all residential tariffs in India use this method to keep low-consumption households on a low effective rate. The opposite (non-telescopic) is used for some high-usage commercial categories where crossing a slab moves the entire bill to the top rate.

Why does TNEB give the first 100 units free?

Tamil Nadu's residential A-1 tariff treats the first 100 units per billing cycle as a free quota — the state government reimburses TNEB for the foregone revenue out of the consumer welfare subsidy. The policy targets low-income households whose monthly consumption stays under 100 units. Once you cross 100 units, the entire bill is computed at the higher slabs starting from unit 101 — the first 100 remain free only if total consumption stays under 100. The slab schedule above 100 units jumps quickly: 101-200 @ ₹2.35, 201-400 @ ₹4.70, 401-500 @ ₹6.30, 501-600 @ ₹8.40, 601-800 @ ₹9.45, 801-1000 @ ₹10.50, 1000+ @ ₹11.55.

What is electricity duty?

Electricity duty is a state-level tax levied on the energy charge portion of the bill — typically 5-16% depending on the state. It is collected by the discom and remitted to the state government. Maharashtra has the highest at 16%, while Tamil Nadu charges 0% on residential supply. The duty is computed on the energy charge alone (not on the fixed charge), and the GST exemption for electricity does NOT extend to duty — duty is a separate state levy under the Electricity Duty Act of each state, not under the CGST/SGST framework.

Is electricity subject to GST?

No — electricity supply is exempt from GST under §9(2) of the Central Goods and Services Tax Act 2017. This was a deliberate carve-out at the time GST was introduced in 2017 to avoid disrupting the existing state-level electricity tax structure. However, this exemption applies only to the supply of electricity itself — state electricity duty (5-16%) still applies as a separate non-GST levy. Also, ancillary services billed by the discom (e.g. consultancy, late-payment fees in some states, certain meter-rental fees) may attract 18% GST. For residential bills, GST is effectively always zero.

Electricity Bill Calculator — Units to Cost by State

Electricity Bill

✨ Lifestyle

Electricity Bill Calculator (State-wise)

Calculate monthly electricity bill across 8 major state discoms (MSEDCL Maharashtra / BESCOM Karnataka / TNEB Tamil Nadu / BSES Delhi / KSEB Kerala / UPPCL UP / TSSPDCL Telangana / APSPDCL Andhra). Applies state-specific slab tariff structure + fixed charges + electricity duty + GST.

Reviewed by the CalculatorKosh Editorial TeamUpdated June 2026Free · No sign-up

Units consumed (kWh)

kWh

01000000

Typical urban household: 200-400 units/month.

Your state / discom

Tariffs reflect FY 2025-26 orders for standard urban residential (LT-1) connections.

Total monthly bill

₹2,485.70

(250 units × avg ₹9.94/unit · Maharashtra (MSEDCL))

Energy charge

₹2,033

Σ slabs × units

Fixed charge

₹128

per month

Duty

₹325

16% of energy

Avg rate

₹9.94/unit

all-in per kWh

Slab-by-slab breakdown

Each unit charged at the slab it falls into (telescopic).

Slab (units)	Units in slab	Rate (₹/kWh)	Charge
1–100	100	₹4.86	₹486.00
101–300	150	₹10.31	₹1,546.50
301–500	0	₹14.85	₹0.00
Energy charge			₹2,032.50

State comparison

Same 250 units priced across discoms — cheapest first.

1Tamil Nadu (TNEB)
₹705
2Delhi (BSES / TPDDL)
₹991
3Andhra Pradesh (APSPDCL)
₹1,267
4Telangana (TSSPDCL)
₹1,275
5Kerala (KSEB)
₹1,580

Bill across all 8 discoms — same 250 units

How to reduce your bill

Switch to a 5-star inverter AC — saves about 30% on cooling load (the single largest household consumer in summer).
Replace remaining CFL/incandescent bulbs with LEDs — cuts lighting energy by 70-80%, around 8-10% off the total bill.
Time-switch the water heater (geyser) — set a 15-30 min timer instead of leaving it on; saves 5-8% off the monthly bill.
Unplug standby loads — set-top box, TV, microwave, charger bricks draw 5-10W constantly. Together that's 50-80 kWh/month of phantom load.

Want a deeper cut?

Reduce your bill with rooftop solar — use the Solar ROI Calculator to see how long the panels pay for themselves at your tariff. →

How It Works

Residential electricity bills are made up of four parts: an energy charge (units priced at a slab schedule), a flat fixed charge per connection, an electricity duty levied by the state (5-16% of the energy charge), and GST — which is effectively 0% for residential supply since electricity is exempt under §9(2) of the CGST Act.

Telescopic slab pricing

Almost every state uses telescopic billing: each unit consumed is charged at the slab it falls into, not the entire bill at the top-slab rate. So if you consume 250 units in Maharashtra (MSEDCL), the first 100 units are charged at ₹4.86, the next 150 at ₹10.31 — energy charge = ₹2,032.50.

Why bills differ so much across states

The same 250 units can cost ₹600 in Andhra Pradesh and ₹2,500 in Maharashtra. The drivers are: per-slab rates (Maharashtra leads the country at ₹14.85/unit above 300 units), fixed charges (₹0-₹128/month), electricity duty (0% in Tamil Nadu vs 16% in Maharashtra), and the presence of cross-subsidies — Tamil Nadu, for example, fully subsidises the first 100 units, while Karnataka's Gruha Jyothi scheme caps the first 200 units for eligible households.

How to reduce your bill

The largest residential load is space cooling (AC + fans) — about 45-55% of summer consumption. A 5-star inverter AC uses 30-40% less power than a 3-star fixed-speed unit. LED lighting saves 8-10% off the total bill. Time-switching the water heater (geyser) saves another 5-8%. For deeper cuts, rooftop solar — under the PM Surya Ghar Muft Bijli Yojana — covers the upfront capital and can wipe out 70-90% of a typical bill.

Frequently Asked Questions

Residential electricity bills add four components:

Energy charge — units consumed priced at the state's slab tariff (telescopic).
Fixed charge — flat monthly amount per connection (₹0-₹128 typical for residential).
Electricity duty — state-level levy of 5-16% on the energy charge.
GST — 0% for residential supply (electricity is exempt under §9(2) of the CGST Act).

Total = Energy charge + Fixed charge + Electricity duty + GST.