Energy · Backup power · Electrical planning

Make sense of the numbers. Plan with confidence.

Calculate energy costs, battery runtime and solar capacity. See the inputs, the formula and what the result does—and does not—tell you.

Calculate electricity cost Find a calculator or reference

A calculation you can check

Appliance power: 1 000 W
Daily use: 2 hours
Period: 30 days

1 000 ÷ 1 000 × 2 × 30

Energy consumed60 kWh

USD 9.00

Example tariff: 0.15 USD/kWh. This is not a local utility tariff.

What are you planning?

Start with a practical question. Each tool explains its assumptions and limitations.

How long will my battery last?

Account for usable capacity, losses and the actual load.

How many solar panels do I need?

Convert daily consumption and peak sun hours into a module count.

What happens over a long cable?

Check voltage drop, then verify ampacity and protection separately.

Already know your consumption in kWh?

Enter meter consumption and a tariff directly. Or calculate consumption from appliance power, daily use and the number of days.

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No account. No saved calculation history.
Calculation inputs stay in your browser. An estimate is not a certified electrical design.

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See how it works

An introduction to the calculators and reference catalogue.

This calculator provides an estimate for informational purposes only. It is not a certified engineering design, electrical safety approval, or professional installation recommendation. Always verify final decisions with a qualified professional and applicable local codes.