Solar subsidy calculator for India
Enter your state and monthly electricity bill to see the right rooftop solar size, your PM Surya Ghar subsidy, the net cost after subsidy, monthly savings and payback — free, instant, no sign-up.
How the solar subsidy calculator works
- Units from your bill. Your monthly bill is divided by the tariff (₹ per unit) to estimate how many units you use each month. Check the units on your bill and adjust the tariff if your slab rate is different.
- System size. Monthly units are divided by what one kW of panels generates in a month in your state (roughly 3.8–4.8 units per kW per day, depending on sunshine). The answer is rounded to the nearest 0.5 kW and capped by your shadow-free roof area (about 90 sq ft per kW).
- Subsidy. PM Surya Ghar central financial assistance is applied: ₹30,000 per kW for the first 2 kW and ₹18,000 for the third kW, capped at ₹78,000 — or ₹33,000, ₹19,800 and ₹85,800 in special-category states and UTs.
- Savings and payback. Year-one savings are the units you avoid buying multiplied by your tariff. Over 25 years we assume panels lose about 0.5% output a year and tariffs rise about 3% a year. Payback is when cumulative savings cover what you paid after subsidy.
PM Surya Ghar subsidy by system size
| System size | Central subsidy (most states) | Special-category states & UTs |
|---|---|---|
| 1 kW | ₹30,000 | ₹33,000 |
| 2 kW | ₹60,000 | ₹66,000 |
| 3 kW | ₹78,000 | ₹85,800 |
| Above 3 kW | ₹78,000 (capped) | ₹85,800 (capped) |
These are the central amounts for individual homes as of September 2026. Group housing societies and RWAs have separate rules, and some states pay an extra top-up. Confirm current rules on the official PM Surya Ghar portal before you apply. Read our full PM Surya Ghar subsidy guide for eligibility and the application steps.
Assumptions and limits
- Residential, on-grid (net-metered) systems without batteries.
- Tariffs are typical mid-slab residential rates per state and can be edited; fixed charges and taxes on your bill are not separated out.
- Panel size is 550 W; roof area needed is about 90 sq ft of shadow-free space per kW.
- CO₂ saved uses about 0.72 kg per unit, close to India's grid emission factor published by the Central Electricity Authority.
- Excess units exported to the grid are not counted as extra savings, because settlement rates differ by state.
For solar installers
Every number on this page is what your customer should see before they sign. PitchSun turns it into a branded, interactive proposal with the roof design, bill of materials, EMI options and e-sign — shared on WhatsApp from the site visit. Join the early-access list.
Solar calculator FAQs
How much subsidy will I get for a 3 kW rooftop solar system?
Under PM Surya Ghar, a 3 kW residential system gets ₹78,000 of central financial assistance: ₹30,000 per kW for the first 2 kW plus ₹18,000 for the third kW. Special-category states and UTs get ₹85,800.
Is there more subsidy for systems bigger than 3 kW?
No. For individual homes the central subsidy is capped at ₹78,000 (₹85,800 in special-category states), so a 5 kW or 10 kW system gets the same central subsidy as a 3 kW system. Some states add their own top-up.
How does the calculator decide the system size?
It converts your monthly bill into units using the tariff, then divides by how many units one kW produces in a month in your state. The result is rounded to the nearest 0.5 kW and limited by the shadow-free roof area you enter.
Does the cost include GST?
Enter your all-in installed cost per kW, including GST, structure and net-metering charges. The default of ₹55,000 per kW is only a starting point; ask your installer for their actual quote.
How accurate is this solar savings calculator?
It gives an indicative estimate. Real generation depends on shade, roof direction, dust and weather, and savings depend on your DISCOM's tariff slabs and net-metering rules. A site survey by an installer gives the final numbers.