Work out an appliance’s wattage from volts and amps, or from a typical preset, plus daily energy use.
Result
How to use this tool
Choose a typical appliance or custom to use volts and amps.
Enter voltage and current for a custom appliance.
Enter how many hours per day it runs.
Read wattage, daily and monthly energy, and monthly cost.
Formula & worked example
A 230 V appliance drawing 2 A uses 460 W, which is 2.30 kWh over 5 hours a day.
Limitations — read this before you rely on it
Volts x amps gives apparent power; inductive loads may differ, presets are typical values only, and monthly figures assume constant daily use.
Frequently asked questions
Electrical power is voltage times current; for AC loads this is apparent power, close to real power for resistive appliances.
Inductive loads draw extra reactive current, so volts x amps can overstate real watts; use the rating plate where possible.
No, they are typical values for comparison; always check the appliance rating plate for the real figure.
It is a standard planning simplification; multiply daily energy by the actual days in the month for an exact bill period.
This tool finds the wattage itself; a cost calculator starts from a known wattage and prices it.