# What your appliances cost per month: watts, hours and units explained

> Your bill is a count of units, and one unit is one kilowatt-hour. A 1.5-ton AC running 8 hours a day uses about 288 units a month, which at ₹8 a unit is ₹2,304. A ceiling fan for 10 hours costs ₹168. This guide shows the formula and which appliances really drive the bill.

Published 2026-10-08 by Toolcloak. 4 minute read. Original: https://toolcloak.pages.dev/articles/what-your-appliances-cost-per-month-watts-hours-and-units-explained
Related free tool: [Electricity Cost Calculator](https://toolcloak.pages.dev/tools/electricity-cost-calculator)

Electricity feels invisible until the bill arrives. Then it is one big number with no explanation. The good news is that the arithmetic behind it is only three steps, and once you can do it for one appliance you can find the two or three that are really costing you.

> **In short**
> - **Units (kWh) = watts × hours ÷ 1,000.** **Cost = units × rate per unit.**
> - At an example rate of **₹8 a unit**, a 1.5-ton AC for 8 hours a day costs about **₹2,304 a month**. A ceiling fan for 10 hours costs about **₹168**.
> - In our sample home, the AC is **about 60% of the bill**. Cooling and heating appliances matter far more than lights.
> - Tariffs differ by state, slab and season, and your wattage may differ from our figures. Treat this as a method, then plug in your own numbers.

## Watts, kilowatts and units

A **watt** measures how fast an appliance uses energy right now. A **kilowatt** is 1,000 watts. A **unit** on your bill is one kilowatt used for one hour, written kWh. So a 1,000 W heater running for one hour uses one unit.

> **Units per day = watts × hours ÷ 1,000:** A 100 W TV on for 4 hours: 100 × 4 ÷ 1,000 = 0.4 units a day. Over 30 days that is 12 units. At ₹8 a unit, ₹96 a month.

## A sample home, appliance by appliance

These are rough figures for a typical flat. An inverter AC draws less than its rating while the compressor idles, so we use an average of 1,200 W while it is on. A fridge cycles on and off, so we use a typical daily total.

| Appliance | Power | Daily use | Units a month | Cost at ₹8 |
| --- | --- | --- | --- | --- |
| 1.5-ton AC | 1,200 W | 8 hours | 288 | ₹2,304 |
| Geyser | 2,000 W | 1 hour | 60 | ₹480 |
| 3 ceiling fans | 70 W each | 10 hours | 63 | ₹504 |
| Refrigerator | cycles | 24 hours | 30 | ₹240 |
| TV | 100 W | 4 hours | 12 | ₹96 |
| 6 LED bulbs | 9 W each | 6 hours | 9.7 | ₹78 |
| Wi-Fi router | 12 W | 24 hours | 8.6 | ₹69 |

*Total about 471 units, or roughly ₹3,770 a month at a flat ₹8 a unit.*

**Monthly cost by appliance (₹, at ₹8 a unit)**

|  | Cost |
| --- | --- |
| 1.5-ton AC | ₹2304 |
| 3 ceiling fans | ₹504 |
| Geyser | ₹480 |
| Refrigerator | ₹240 |
| TV | ₹96 |
| 6 LED bulbs | ₹78 |
| Wi-Fi router | ₹69 |

*One appliance outspends the other six combined. If you want to save, start at the top.*

**Share of the sample bill**

|  | Share |
| --- | --- |
| AC | 61% |
| Fans | 13% |
| Geyser | 13% |
| Fridge | 6% |
| Everything else | 6% |

Try it: [Electricity Cost Calculator](https://toolcloak.pages.dev/tools/electricity-cost-calculator). Enter watts, hours a day and your rate to get the daily, monthly and yearly cost.

## What an hour more of AC costs

Because cost scales in a straight line with hours, you can feel the effect of each extra hour. For the 1,200 W AC at ₹8 a unit, each hour costs ₹9.60, and each extra hour a day adds about ₹288 a month.

**Monthly AC cost by hours of use per day (₹ thousand)**

| Hours a day | AC cost a month |
| --- | --- |
| 0 | 0 |
| 2 | 576 |
| 4 | 1152 |
| 6 | 1728 |
| 8 | 2304 |
| 10 | 2880 |
| 12 | 3456 |

*Going from 6 to 8 hours adds ₹576 a month. Setting the thermostat 1 degree higher, a common tip, saves a few percent of the AC’s consumption.*

## Small things add up differently

Replacing a 60 W old-style bulb with a 9 W LED saves 51 W. At 6 hours a day that is about 112 units a year per bulb, roughly ₹890 at ₹8 a unit. Across six bulbs, it comes to over ₹5,000 a year. That is a bigger win than most people expect, but still smaller than one fewer hour of AC each day all summer.

**One bulb, one year, 6 hours a day**

| 60 W old bulb | 9 W LED |
| --- | --- |
| 131 units | 20 units |
| About ₹1,051 a year at ₹8 | About ₹158 a year at ₹8 |
| Also gives off a lot of heat | Saves about ₹893 a year |

## Why your bill may not match the sum

- **Slabs.** Many states charge more per unit as your usage rises. The last units can cost more than the first, so the average rate is not the same as the top rate.
- **Fixed and other charges.** Fixed charges, fuel adjustments and taxes are added on top of the energy charge.
- **Standby power.** TVs, set-top boxes and chargers draw a little even when “off”. It is small per device but runs 24 hours a day.
- **Real watts differ from the label.** The sticker shows the maximum. Use a plug-in power meter if you want the real figure.
- **Season.** Summer and winter use differ a lot. Use a yearly average if you want to budget.

## Five ways to cut the bill

1. **Raise the AC thermostat and use a fan with it.** Every degree helps, and a fan moves the air at 70 W instead of 1,200 W.
2. **Cut geyser time.** Heat only what you need and switch off after use. A timer helps.
3. **Service the AC and fridge.** Clean filters and coils let them work with less power.
4. **Choose a high star rating when you replace a big appliance.** A 5-star unit uses less per year, which pays back over its life.
5. **Switch off at the wall.** Use a power strip for the TV, set-top box and chargers.

> **Find the big three first:** Write down the power and daily hours for every appliance over 500 W. Those usually explain most of your bill. Check small ones only after you have dealt with the big ones. If you also run a home business, our [break-even guide](https://toolcloak.pages.dev/articles/break-even-point-how-many-sales-before-you-make-a-profit) shows how to treat the bill as a fixed cost.

## Frequently asked questions

### How do I calculate electricity cost for an appliance?

Units = watts × hours ÷ 1,000. Cost = units × your rate per unit. For a 100 W TV used 4 hours a day, that is 0.4 units a day.

### What is one unit of electricity?

One unit is one kilowatt-hour (kWh): 1,000 watts used for one hour.

### How much does a 1.5-ton AC cost per month?

At about 1,200 W for 8 hours a day and ₹8 a unit, roughly ₹2,300 a month. Your actual cost depends on the model, the room, the weather and your tariff.

### Why is my bill higher than my calculation?

Slab rates, fixed charges, taxes and standby power are not in the simple formula, and real wattage can differ from the label.

### How can I find the real power of an appliance?

Use a plug-in energy meter, or read the label and remember that it shows the maximum draw, not the average.