Electricity

Free Solar Panel Calculator

How many kW and panels for your home or shop — from your appliances or your bill.

From load or bill Panels count Nothing uploaded

See the letter and download ↓

Estimate for

Name / site (optional)

Date

How much power you use

Work it out from

Appliance	Watts	How many	Hours a day

Watts are on the label or in the manual of each appliance. Use the real numbers of your home or shop.

Sun and panels

Peak sun hours a day at your place

Ask your installer, or see solar data for your district. The page does not assume a figure.

Watts of one panel

From the panel you were quoted (written on it as Wp).

Losses %

Rule of thumb for heat, dust, wiring and inverter losses — change it to your installer’s figure.

Prices (optional)

Fill in the prices you were quoted to get a cost estimate. Leave empty for quantities only.

Price per kW (₹)

Everything you type stays in your browser — nothing is uploaded or saved.

Sun hours and losses are your inputs.

What this tells you

How many kW of panels make the energy you use, from your appliances or your bill. The sunshine figure (peak sun hours) changes from place to place and season to season — take it from your installer or the solar data for your district. For backup at night, see the inverter and battery calculator.

Kaise use karein

Appliance ke watt, sankhya aur ghante bharein — ya bill ke units.
Apni jagah ke peak sun hours aur panel ke watt bharein.
kW aur panel ki sankhya dekhein; PDF download karein.

Dhyan dein

Sun hours jagah ke hisaab se badalte hain — installer se poochhein.

Questions people ask

How many solar panels do I need?

Work out the energy you use a day (watts × hours of each appliance, or units on the bill ÷ days). Divide by the peak sun hours at your place and by (1 − losses), then by the watts of one panel, and round up.

What are peak sun hours?

The number of hours of full-strength sunshine a day that gives the same energy as the whole day’s sun. It differs by place and season; your installer or the solar data for your district gives it. The page does not assume a figure.

Why is there a losses %?

Panels give less than their label because of heat, dust, wiring and the inverter. 25% is a rule of thumb you can change to your installer’s figure.

Does it include subsidy?

No. Subsidy and net-metering rules come from the government scheme and your electricity board; ask your installer or the official portal.

Is my data uploaded?

No. Everything is worked out in your browser.

Related tools

Questions & problems

Ask a question or tell us if something didn’t work. Messages are private — only the ToolNinja team reads them, nothing is shown on this page.