Electricity Unit Calculator — kWh to Bill & Appliance Cost (India)
Calculate electricity units (kWh) consumed by any appliance and estimate your monthly bill. Slab-wise tariff calculator for Indian states.
Understanding electricity units is the first step to controlling your bill. One unit = 1 kWh = running a 1,000-watt appliance for 1 hour. The CalcHub Electricity Unit Calculator converts appliance wattage and usage time into units consumed and estimated cost.
The Core Formula
Units (kWh) = Wattage × Hours Used × Days / 1,000 Monthly Cost = Units × Rate per UnitAppliance-by-Appliance Consumption
| Appliance | Wattage | Daily Use | Monthly Units | Cost (₹8/unit) |
|---|---|---|---|---|
| LED bulb (9W) | 9W | 8 hrs | 2.2 | ₹17 |
| CFL bulb (15W) | 15W | 8 hrs | 3.6 | ₹29 |
| Ceiling fan | 75W | 12 hrs | 27 | ₹216 |
| Table fan | 50W | 8 hrs | 12 | ₹96 |
| Air cooler | 200W | 10 hrs | 60 | ₹480 |
| 1T AC (3-star) | 1,100W | 8 hrs | 264 | ₹2,112 |
| 1.5T AC (5-star inverter) | 900W (avg) | 8 hrs | 216 | ₹1,728 |
| Refrigerator (190L) | 120W (avg) | 24 hrs (cycles) | 45 | ₹360 |
| Refrigerator (300L) | 180W (avg) | 24 hrs | 65 | ₹520 |
| Washing machine | 500W | 1 hr | 15 | ₹120 |
| Microwave | 1,200W | 15 min | 9 | ₹72 |
| Electric iron | 1,000W | 30 min | 15 | ₹120 |
| Electric geyser (25L) | 2,000W | 30 min | 30 | ₹240 |
| Instant geyser | 3,000W | 10 min | 15 | ₹120 |
| TV (LED 43") | 80W | 6 hrs | 14.4 | ₹115 |
| Desktop computer | 300W | 8 hrs | 72 | ₹576 |
| Laptop | 65W | 8 hrs | 15.6 | ₹125 |
| Wi-Fi router | 12W | 24 hrs | 8.6 | ₹69 |
| Phone charger | 20W | 2 hrs | 1.2 | ₹10 |
| Mixer grinder | 750W | 15 min | 5.6 | ₹45 |
| Induction cooktop | 2,000W | 1 hr | 60 | ₹480 |
| Water purifier (RO) | 60W | 3 hrs | 5.4 | ₹43 |
| Hair dryer | 1,500W | 10 min | 7.5 | ₹60 |
Total Monthly Bill Estimation
Typical 2BHK household (summer):| Appliance | Qty | Monthly Units |
|---|---|---|
| LED bulbs | 8 | 17.6 |
| Ceiling fans | 4 | 108 |
| 1.5T AC (inverter) | 1 | 216 |
| Refrigerator | 1 | 50 |
| TV | 1 | 14.4 |
| Washing machine | 1 | 15 |
| Geyser | 1 | 15 |
| Misc (router, chargers, etc.) | — | 20 |
| Total | ~456 units |
- 0–100 units: 100 × ₹4 = ₹400
- 101–200: 100 × ₹5.50 = ₹550
- 201–300: 100 × ₹7 = ₹700
- 301–400: 100 × ₹8.50 = ₹850
- 401–456: 56 × ₹10 = ₹560
- Total energy charge: ~₹3,060 + fixed charges + duty ≈ ₹3,500–3,800
Star Rating Impact
| Appliance | 3-Star | 5-Star | Monthly Saving | Annual Saving |
|---|---|---|---|---|
| 1.5T AC (8 hr/day) | 384 units | 216 units | 168 units (₹1,344) | ₹8,060 |
| Refrigerator | 65 units | 38 units | 27 units (₹216) | ₹2,592 |
| Ceiling fan | 27 units | 18 units | 9 units (₹72) | ₹864 |
How to Use the Calculator
- Open the CalcHub Electricity Unit Calculator
- Enter appliance wattage (check the label or manual)
- Enter daily usage hours
- Enter electricity rate (₹/unit)
- See: monthly units consumed and estimated monthly cost
How do I find my appliance's wattage?
Check the label/sticker on the appliance (usually on the back or bottom). It shows wattage (W) or power (VA). If only amps are listed: Watts ≈ Amps × 220 (India voltage). For appliances like ACs and refrigerators, the rated wattage is the maximum — actual average consumption is lower.
Why does my actual bill differ from the calculation?
Several reasons: (1) Appliances don't run at full wattage constantly (ACs cycle, refrigerator compressor cycles). (2) Slab rates change your effective rate. (3) Fixed charges, duty, and surcharges add 15–25% beyond energy charges. (4) Meter reading dates may not match calendar months.
Is solar worth it for reducing electricity bills?
A 3 kW rooftop solar system costs ₹1.5–2 lakh (after subsidy) and generates ~350–400 units/month. If your bill is ₹3,000+/month, solar pays for itself in 4–5 years and then generates free electricity for 20+ years.
Related Calculators
- Solar Panel Calculator — rooftop solar sizing
- Energy Savings Calculator — appliance upgrade ROI
- Power Converter — watts, kW, HP conversions
- BTU Calculator — AC sizing for your room