Free solar calculators

Every solar calculator in one place

Size your array from the electric bill, price it after local incentives, check the payback, and size batteries for backup — every tool is free and runs entirely in your browser.

Calculators by country

US solar calculator

Size, 30% ITC cost & payback

UK solar calculator

Size, 0% VAT cost & SEG payments

India solar calculator

Size, PM Surya Ghar cost & payback

Australia solar calculator

Size, STC cost & feed-in tariffs

Pakistan solar calculator

Size, net metering & backup sizing

Philippines solar calculator

Size, Meralco rates & net metering

Calculators by job

Solar system calculator

Inverter kW & battery kWh for backup

Solar cost calculator

Price any system in 6 currencies

Solar ROI calculator

Payback years & 25-year savings

Battery size calculator

Bank kWh, amp-hours & battery count

Panel output calculator

Daily, monthly & annual kWh

Start with your bill on a country calculator, price the system with the cost calculator, then confirm the investment with the ROI calculator.