What this calculator does
The Whole Home Electricity Bill Calculator estimates your total power bill by adding up the energy used by your biggest appliances and applying your utility's per-kWh rate plus any fixed service charge. It works in any country and any currency because you supply your own rate and fee — there are no built-in tariffs or assumptions.
How to use it
For each device — air conditioner, refrigerator, lighting, and "other" (TVs, computers, washing machine, etc.) — enter the power rating in watts and how many hours per day it typically runs. Then enter the number of days in your billing period (usually 30), your rate per kilowatt-hour, and your provider's fixed monthly fee. The calculator returns your estimated bill plus a breakdown of daily and total consumption.
The formula explained
Energy in kilowatt-hours equals watts \(\times\) hours \(\div\) 1000. We compute each device's daily kWh, sum them, multiply by the number of days to get total kWh, multiply that by your rate to get the energy cost, and finally add the fixed fee:
$$\text{Bill} = \left( \frac{E}{1000} \times \text{Days} \times \text{Rate} \right) + \text{Fixed Fee}$$ $$\text{where}\quad \left\{ \begin{aligned} E &= \text{AC W}\cdot\text{AC h} + \text{Fridge W}\cdot\text{Fridge h} \\ &\quad + \text{Light W}\cdot\text{Light h} + \text{Other W}\cdot\text{Other h} \end{aligned} \right.$$
Worked example
An AC (\(1500\ \text{W} \times 6\ \text{h} = 9\ \text{kWh/day}\)), a fridge (\(150\ \text{W} \times 24\ \text{h} = 3.6\ \text{kWh/day}\)), lighting (\(200\ \text{W} \times 5\ \text{h} = 1\ \text{kWh/day}\)), and other devices (\(300\ \text{W} \times 4\ \text{h} = 1.2\ \text{kWh/day}\)) total 14.8 kWh/day. Over 30 days that's 444 kWh. At 0.15 per kWh the energy cost is 66.60; add a 10 fixed fee and the bill is 76.60.
$$14.8\ \text{kWh/day} \times 30\ \text{days} = 444\ \text{kWh}$$ $$444 \times 0.15 = 66.60$$ $$66.60 + 10 = 76.60$$
FAQ
Where do I find a device's wattage? Check the label on the appliance, its manual, or a plug-in power meter. AC and heaters are the biggest drivers.
Why is my estimate off from my real bill? Usage hours vary, motors cycle on and off, and tiered rates or taxes may apply. Treat this as a planning estimate.
Can I use it for any currency? Yes — enter the rate and fixed fee in your own currency and the result is in that same currency.
