Daily Energy Consumption Calculator
Work out daily and monthly energy consumption from appliance wattage and running hours before sizing any solar system.
Results
Start here, not with the panels
Every other calculation on this site depends on this one. Array size, battery bank, inverter rating and payback period all follow from how much energy the building actually uses, and a system designed on a guess is a system that disappoints.
Standby loads are not noise
A set-top box drawing 3 W around the clock uses more in a year than a kettle boiled twice a day. Across a typical home, standby loads often account for 5 to 10 % of the bill, and in an off-grid system they drain the battery through the night when nothing is generating.
Common mistakes
Using nameplate wattage as if it ran flat out. A 2,000 W kettle uses 2 kW only while boiling; a fridge marked 150 W cycles on and off and averages a fraction of that. Where a figure matters, a plug-in meter over a week beats any estimate.
Questions people ask
Should I use my bill instead? Yes, if you have one — annual kWh divided by 365 is the most reliable daily figure there is. Appliance-by-appliance addition is for new builds and for finding out where the energy actually goes.
Does seasonality matter? Considerably. Heating, lighting and pumping all shift the profile, and an off-grid system has to survive the worst month, not the average one.