Solar calculators for the rooftops India is actually installing
Subsidy, savings, system size and the AC bill — four calculators built around India's rooftop solar push and the electricity you already pay for.
All Solar & Energy calculators
Enter your rooftop system size and get the PM Surya Ghar central subsidy slab by slab, plus what you actually pay…
Open calculatorEnter your system size, tariff and sun hours to see annual savings, the payback period and the simple 25-year…
Open calculatorWork backwards from your monthly electricity use to the kW your roof needs, the number of panels and the area they…
Open calculatorPut in your AC's power draw and running hours to get units per day, per month and per year — and what those units…
Open calculatorWhat this vertical covers
Rooftop solar has moved from an enthusiast purchase to a household decision. The PM Surya Ghar scheme pays a fixed central subsidy, states add their own, and the payback now often lands inside five years. The hard part is not the technology — it is the arithmetic.
These calculators answer the four questions people actually ask before signing: what subsidy will I get, will it pay back, what size do I need, and how much of my bill is the AC? Every assumption that changes by city, discom or month — tariff, sun hours, installed cost — is an editable input, not a hidden constant.
The solar subsidy rates and benchmark costs come from the MNRE scheme guidelines. Electricity tariffs and panel prices do not, so they are shown as dated, editable defaults and should be replaced with your own bill and quote.
Worth knowing before you calculate
The central subsidy stops at 3 kW
PM Surya Ghar pays ₹30,000 per kW for the first 2 kW and ₹18,000 for the third, with nothing beyond. The maximum a home can get centrally is ₹78,000.
Rooftop solar often repays in 3–5 years
At a subsidy-supported price and a tariff above ₹7 a unit, a clean 3 kW system usually recovers its cost within four years — before the panels' 25-year life is considered.
The AC is usually the biggest unit on the bill
A 1.5-ton AC running eight hours a day can use about 12 units daily — more than a 3 kW rooftop system generates. Sizing the roof to the load is the whole game.
Solar & Energy — frequently asked questions
What is the maximum PM Surya Ghar subsidy?+
Do these calculators use official electricity tariffs?+
What size solar system do I need?+
How do I verify the scheme details?+
Are these calculators useful without a rooftop system?+
Every calculator, dated and sourced.
Each calculator on this page is generated from one verified record: its inputs, formula, tests, sources and the date the numbers were checked. When an official rate changes, the record changes and the page is rebuilt with a new verified date.
Sources for this vertical
This hub
- Last verified: 29 October 2026
- Calculators live: 4
- Read the methodology
How we handle errors
- Spotted a mistake? Report it — we correct and log it.
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