The one formula you need
Units = watts × hours ÷ 1000
- A 1,000-watt iron used for one hour = 1 unit.
- A 9-watt LED bulb on for 6 hours = 9 × 6 ÷ 1000 = 0.054 units a day, about 1.6 units a month.
- A 2,000-watt geyser heating for 45 minutes = 2,000 × 0.75 ÷ 1000 = 1.5 units a day, about 45 a month.
Two corrections make the answer realistic:
- Thermostats and compressors cycle. A fridge, AC, geyser or iron does not draw full power all the time. Use the BEE star label's annual kWh figure where there is one, not the nameplate watts.
- Motors draw more than their rating. A "1 HP" pump is rated at 746 watts of output. Its input from the supply is higher, typically 900 to 1,100 watts, depending on the pump's efficiency.
Typical units per month
The figures below are typical, based on BEE star-label consumption figures and common manufacturer ratings. Your own appliance's label or nameplate will differ. Cost is at the ₹5.80 energy charge only. Add roughly 15% for the 35 paise surcharge and 9% tax, which gives about ₹6.70 a unit. The fixed charge does not change with appliance use.
| Appliance | Typical power / basis | Usage assumed | Units / month | Cost / month at ₹5.80 |
|---|---|---|---|---|
| AC 1 ton, 5-star inverter | ~0.35–0.45 units/hour average | 8 h/day | 85–110 | ₹490–640 |
| AC 1.5 ton, 5-star inverter | ~700–850 kWh/year on label (1,600 h) → ~0.45–0.55/hour | 8 h/day | 110–130 | ₹640–750 |
| AC 1.5 ton, 3-star inverter | ~0.6–0.7/hour | 8 h/day | 145–170 | ₹840–990 |
| AC 1.5 ton, non-inverter (fixed speed) | ~1.0–1.3/hour with compressor cycling | 8 h/day | 240–310 | ₹1,390–1,800 |
| AC 2 ton, 5-star inverter | ~0.65–0.8/hour | 8 h/day | 155–190 | ₹900–1,100 |
| Fridge, single door ~190 L | ~120–200 kWh/year on label | 24 h | 10–17 | ₹60–100 |
| Fridge, double door ~250 L, 3-star | ~230–260 kWh/year | 24 h | 19–22 | ₹110–130 |
| Fridge, double door ~250 L, 5-star | ~175–190 kWh/year | 24 h | 15–16 | ₹85–95 |
| Storage geyser 15–25 L | 2,000 W heater | 45 min/day heating | ~45 | ~₹260 |
| Instant geyser 3 L | 3,000 W | 20 min/day | ~30 | ~₹175 |
| Washing machine, no heater | ~0.2–0.4 units per wash | 20 washes | 4–8 | ₹25–45 |
| Front-load with hot wash | ~1–1.5 units per hot wash | 20 washes | 20–30 | ₹115–175 |
| Water pump 1 HP | ~1,000 W input | 1 h/day | ~30 | ~₹175 |
| Water pump 0.5 HP | ~550 W input | 40 min/day | ~11 | ~₹65 |
| Iron (dry) | 750–1,000 W, thermostat cycles | 20 min/day | 6–10 | ₹35–60 |
| LED TV 32" | 30–50 W | 5 h/day | 5–8 | ₹30–45 |
| LED TV 43"–55" | 60–110 W | 5 h/day | 9–17 | ₹55–100 |
| Ceiling fan, ordinary | 70–75 W | 12 h/day | ~27 | ~₹155 |
| Ceiling fan, BLDC 5-star | ~28–35 W | 12 h/day | 10–13 | ₹60–75 |
| LED bulb | 9 W | 6 h/day | ~1.6 each | ~₹9 each |
| Induction stove | 1,200–2,000 W, power varies with setting | 1 h/day | 35–55 | ₹200–320 |
Hot districts like Kalaburagi, Raichur and Ballari run ACs harder and longer than Bengaluru or Hassan. Expect the top of the AC ranges or more there in April and May.
Air conditioners: the biggest swing in any bill
The BEE label on an AC shows the ISEER (higher is better) and the annual units, worked out for 1,600 hours of cooling a year. That is about 4.4 hours a day across the year, so divide the label figure by 1,600 to get average units per hour. Then multiply by your own hours.
- Inverter vs fixed speed: an inverter compressor slows down once the room is cool instead of switching fully on and off. For long daily use, the inverter models in the table use roughly half the units of an old fixed-speed unit.
- Set 24–26 °C. Each degree lower adds noticeably to the units.
- Size it right. An undersized AC runs flat out all day. A 1.5 ton in a 10×12 ft west-facing bedroom under an RCC roof is common, but a 1 ton will struggle in Karnataka's summer.
- Wiring: a 1.5 or 2 ton AC needs its own circuit with a correctly rated MCB and cable. Check your sanctioned load too. See load enhancement.
What this means for Gruha Jyothi
Gruha Jyothi gives free units up to your entitled units (shown on the bill), and none at all in a month when total use crosses 200 units. Two examples:
| Family A | Family B | |
|---|---|---|
| Entitled units | 90 | 150 |
| Base use (fridge, fans, lights, TV, pump, iron) | ~80 | ~110 |
| Add a 1.5 ton 5-star inverter AC, 4 h/night | +~60 → 140 | +~60 → 170 |
| Add a storage geyser | +~45 → 185 | +~45 → 215 |
| Result | Pay for 95 units above entitlement | Over 200: whole month billed |
The 200-unit line is the one to watch. Crossing it by even a few units turns a small bill into a full one. A smart meter or a weekly meter reading lets you see it coming. The rules on entitlement are in our Gruha Jyothi guide, and for new houses and tenants see Gruha Jyothi for new connections.
Small loads that add up
These rarely make the list when people estimate their use, but they run for many hours. Figures are typical. Check your own nameplates.
| Load | Typical power | Usage assumed | Units / month |
|---|---|---|---|
| Home inverter / UPS (charging and standby losses) | varies with battery and power cuts | 24 h connected | often 15–40 |
| RO water purifier | 25–60 W while purifying | 2 h/day | 2–4 |
| Wi-Fi router and set-top box | 10–25 W together | 24 h | 7–18 |
| Desktop computer with monitor | 100–200 W | 6 h/day | 18–36 |
| Laptop | 40–65 W | 6 h/day | 7–12 |
| Mixer grinder | 500–750 W | 15 min/day | 4–6 |
| Microwave oven | 1,000–1,400 W input | 15 min/day | 8–10 |
| Electric kettle | 1,500 W | 10 min/day | ~7.5 |
The home inverter is the one that surprises people most. In areas with frequent cuts, the battery is charged again after every cut, and old batteries waste a good part of that energy as heat. If your inverter is more than five years old and your units have crept up, get the battery and charger checked.
A worked example. A family of four in a 2BHK: fridge 20 units, 4 ordinary fans at 10 hours a day about 90, 8 LED lights 13, TV 10, router and set-top box 12, pump 15, iron 8, washing machine 6, mixer and kettle 12, inverter 20. Total about 200 units, without any AC or geyser. Switching to BLDC fans alone would bring it to around 145 to 150 units.
Do your own 10-minute home audit
Measuring instead of guessing
Tables give typical figures. If you want to know what your own fridge or geyser uses, measure it. There are three simple ways.
- A plug-in energy meter. A small meter that plugs in between the socket and the appliance shows watts and the kWh used over a day or a week. It works well for fridges, TVs, routers and washing machines. It is not for ACs, geysers and pumps on their own 16 A or 20 A circuits unless it is rated for that load.
- The main meter, with everything else off. Switch off every other load, note the kWh reading, run the appliance for an hour, and read again. The difference is its units for that hour. Do it for a full heating cycle for a geyser.
- Counting LED blinks. The meter's LED blinks a fixed number of times per unit, printed as imp/kWh. With only one appliance running, count blinks for one minute. At 3,200 imp/kWh, 40 blinks a minute means 40 × 60 ÷ 3,200 = 0.75 kW. Our meter guide shows where the LED and the rating are.
If a measured figure is far above the label, the appliance may be faulty: a fridge with a torn gasket runs its compressor much longer, and a geyser with a scaled-up element takes longer to heat. If the meter keeps recording with everything off, the units are going somewhere in the wiring. An RCCB trip test and an insulation test find most such leaks; see MCB, RCCB and RCBO. If the wiring is sound and the units still do not add up, it is time for a meter test and a written complaint, as set out in our high bill complaint guide.
For a geyser that runs every day, the long-term fix is often a solar water heater rather than a better timer.
Where the savings really are
- AC hours and temperature matter more than anything else on this list.
- Geyser timer or solar water heater. A storage geyser left on all day keeps reheating as it loses heat.
- BLDC fans in rooms where fans run 12+ hours: about 15 units a month saved per fan.
- Replace a 10+ year old fridge with a 5-star model, especially if the door gasket is torn.
- Pump: fix overhead tank overflow. A float switch costs less than one month's wasted units.
- Rooftop solar if your use is regularly above your free units. See PM Surya Ghar in Karnataka.
The figures here are typical estimates, not measurements of your appliances. Use the BEE star label (beeindia.gov.in) or nameplate of your own appliance for exact figures, and your ESCOM bill for your entitled Gruha Jyothi units and the current tariff. If units cannot be explained, ask your ESCOM subdivision for a meter check.
Questions
How many units does a 1.5 ton AC use per hour?
A 1.5 ton 5-star inverter AC typically averages about 0.45 to 0.55 units per hour over a season, based on its BEE label figure of about 700 to 850 kWh for 1,600 hours. An older non-inverter unit can use 1 to 1.3 units an hour.
How many units does a fridge use per month?
Typically 10 to 22 units a month, depending on size and star rating. Divide the annual kWh on the BEE label by 12 for your model.
How do I calculate electricity units for an appliance?
Multiply the appliance's watts by the hours used, then divide by 1000. That gives units (kWh). For example, 2000 W × 0.5 h ÷ 1000 = 1 unit.
How much does one unit of electricity cost in Karnataka for homes?
The domestic energy charge for 2026-27 is ₹5.80 per unit. With the 35 paise surcharge and 9% electricity tax it is about ₹6.70 per unit, plus a fixed charge on sanctioned load.
Will an AC make me lose Gruha Jyothi?
Only in a month when total use crosses 200 units. Units above your entitled units but below 200 are billed normally. A 1.5 ton inverter AC used 4 hours a night adds roughly 60 units a month.
Does a geyser use a lot of electricity?
A 2,000 W storage geyser heating for about 45 minutes a day uses around 45 units a month. Leaving it on all day uses more, because it keeps reheating.
Sources
Rules and figures in this article were checked against these sources on 30 Sep 2026. Schemes and tariffs change, so confirm with the official office before you act.
- BEE: Schedule for room air conditioners (1600 operating hours basis)
- Down To Earth: What is the star rating label of an AC telling you?
- Onida: How much electricity does a 1.5 ton AC consume
- Bajaj Finserv: How much electricity a refrigerator consumes
- Atomberg: BLDC fan vs normal fan
- Wikipedia: BEE Star Label
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