Electricity Bill Calculator: Estimate Your Monthly Bill (2026)

Every electricity bill comes down to one formula:

Monthly cost = (Wattage × Hours per day × 30) ÷ 1000 × Rate per kWh

Let us break that down:

• Wattage: How much power the appliance uses (printed on the appliance or in the manual)
• Hours per day: How long you run it daily
• ÷ 1000: Converts watts to kilowatts
• × 30: Monthly usage
• Rate per kWh: What your electricity board charges per unit (varies by state and slab)

Example

A 1.5-ton AC rated at 1,500W running 8 hours/day in Maharashtra (₹9.50/kWh for higher slabs):

(1500 × 8 × 30) ÷ 1000 × 9.50 = 360 kWh × ₹9.50 = ₹3,420/month

That single AC costs ₹3,420 per month. Now you know why summer bills are brutal.

Here is the real data most people are surprised by:

The surprise: Your AC costs more per month than your fridge, TV, fans, and lights combined. The geyser is the second biggest offender, especially in winter.

Indian electricity boards use a slab system — the more you use, the higher the per-unit rate. This is why your bill does not double when consumption doubles; it can actually triple or quadruple.

This is why reducing even 50 units matters so much: Those 50 units are charged at the highest slab rate. Dropping from 350 to 300 units does not save you ₹350 — it saves you ₹450+ because those top units were at the expensive rate.

Forget "turn off lights when leaving the room" — that saves ₹30/month. Here are the changes that actually move the needle:

• AC: Set to 24°C, not 18°C. Every degree below 24 increases AC consumption by 6%. Running at 18°C costs almost 40% more than 24°C. Use sleep mode at night.
• Buy a 5-star AC if replacing. A 5-star 1.5T AC uses 1,100W vs 1,500W for a 3-star. That is ₹670/month savings — it pays for the price difference within 2 years.
• Geyser: Use a timer. Set it to heat for 30 minutes before your bath, not all morning. Better yet, get an instant geyser (3kW for 5 min vs storage geyser 2kW for 60 min).
• Replace tube lights with LED. A 40W tube light running 6 hours costs ₹50/month. A 9W LED gives the same brightness for ₹11/month. Multiply that by 8 lights.
• Fridge: Do not open it 20 times a day. Every time you open it, the compressor runs for 10 extra minutes. Decide what you want before opening. Also, keep it 75% full — a full fridge is more efficient than an empty one.
• Use star ratings when buying. Always compare BEE star ratings. A 5-star appliance costs more upfront but saves thousands per year.

Rates vary significantly across India. Here are the average domestic rates for major states:

Note: These are approximate domestic rates. Actual rates depend on your specific distribution company, connection type, and subsidy eligibility. Check your electricity board website for exact slab rates.