Last updated: 21 June 2026
Solar Panel Size Calculator India
Use monthly units and local solar yield to compare common household system sizes, roof area, output and budget.
Independent calculator — not a government website.
Central subsidy slabs
For eligible residential households under PM Surya Ghar.
Up to 1 kW
₹30,000
Up to 2 kW
₹60,000
3 kW or higher
₹78,000
maximum
No extra central subsidy beyond 3 kW.
A practical size starts with monthly use
The calculator estimates the capacity needed to produce roughly the electricity units entered, then rounds up to a practical size: 1, 2, 3, 4, 5, 6, 8 or 10 kW. It keeps lower-use households within the broad size ranges in the brief.
- Up to 150 units a month: typically 1–2 kW
- 150–300 units a month: typically 2–3 kW
- Above 300 units a month: typically 3 kW or more
Do not size from one unusually high month
Use a 12-month average and note future loads such as air conditioning, an electric vehicle or an induction kitchen. Oversizing without understanding export credits can weaken the financial result.
Roof and connection constraints matter
A technically suitable size also depends on shadow-free area, structural condition, sanctioned load, phase, inverter design and current DISCOM rules. Confirm these during a site survey.
Frequently asked questions
Clear answers, with the important caveats left in.
Is a 3 kW system enough for 300 units a month?
Often it is a reasonable starting point. At 4.2 units per kW per day, 3 kW estimates about 378 units per month before site-specific variation.
Can I override the recommended system size?
Yes. Enter a desired size to compare that system's cost, subsidy cap, generation, roof area and payback.
Should I size for my bill or my sanctioned load?
Both consumption and electrical-connection constraints matter. Use consumption for the energy estimate, then confirm sanctioned-load and interconnection limits with your DISCOM.
How accurate is this calculator?
It is a planning estimate based on the values you enter, a state-level solar-yield assumption and the published central subsidy slabs. Shade, roof direction, equipment performance, local tariff design and approval rules can materially change the real outcome.
Is this website official?
No. This is an independent calculator and is not affiliated with the Government of India, MNRE, PM Surya Ghar or any DISCOM. Verify eligibility and subsidy amounts on the official portal and with your DISCOM.
Get rooftop solar quotes
Leave your details for the future quote-matching service. This demo form does not send data anywhere yet.