Watt to unit (kWh) converter
Quickly convert watts × hours of use into electricity units (kWh) per day or month, then into Taka at the rate that applies to your meter.
Convert watts and hours to units
30 for a typical billing month.
Formula: Units (kWh) = Watts × Hours ÷ 1000
Cost: Cost (৳) = Units × Tariff rate (৳ per unit)
Add 5% VAT on top to match the printed bill.
Watts, units, and kWh — explained once and for all
Almost every electricity-bill confusion in Bangladesh comes from mixing up power and energy. Here's the difference, and the one formula you actually need.
The one thing to remember
- Watts = power (instantaneous). Units (kWh) = energy (over time)
- 1 unit = 1 kWh = 1,000 W for 1 hour. There is no other definition
- Formula: Units = Watts × Hours ÷ 1000
The difference
Power vs energy
Watts (W) measure power— the instantaneous draw of an appliance at a single moment. A 100 W bulb pulls 100 watts the whole time it’s on, no matter how long.
Watt-hours (Wh) and kilowatt-hours (kWh) measure energy — how much power flowed over time. A 100 W bulb run for one hour uses 100 Wh = 0.1 kWh.
The formulas
Three forms of the same equation
Memorise these
Common conversions
1,000 W × 1 h
1unit
100 W × 10 h
1unit
500 W × 2 h
1unit
Cost
From units to taka
Multiply units by your tariff rate. The catch is that Bangladesh residential tariff has multiple slabs — your effective rate depends on total monthly consumption.
| Slab (units/month) | Rate (৳/unit) |
|---|---|
| 0–50 (Lifeline) | ৳4.63 |
| 0–75 (1st tier) | ৳5.26 |
| 76–200 | ৳8.50 |
| 201–300 | ৳9.10 |
| 301–400 | ৳9.62 |
| 401–600 | ৳15.01 |
| 600+ | ৳17.35 |
For the exact bill including slabs, demand charge, and VAT, use the monthly bill calculator.
Frequently asked questions
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kWh ↔ unit
1 unit = 1 kWh = 1,000 watt-hours. They are the same quantity under two names, so there is nothing to convert — here is the arithmetic, what it costs in taka, and why watts are a different measure entirely.
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