Solar Savings Calculator
Find the right system size and your savings in seconds.
What size do most homes need?
A rough guide at ₹7.5 per unit. Your own bill and tariff change the answer, so use the calculator above.
| Monthly bill | System size | Roof area | Cost before subsidy |
|---|---|---|---|
| ₹2,000 | 3 kW | 180 sq ft | ₹159,000 |
| ₹4,000 | 5 kW | 300 sq ft | ₹265,000 |
| ₹6,000 | 7 kW | 420 sq ft | ₹371,000 |
| ₹10,000 | 12 kW | 720 sq ft | ₹636,000 |
Roof area = 2 panels per kW × 30 sq ft per panel. As a plot guide, a 20 × 20 ft (400 sq ft) roof fits about 6 kW, and 25 × 50 ft (1,250 sq ft) is plenty for 12 kW. Approximate figures at 120 units per kW per month and ₹53,000 per kW.
PM Surya Ghar subsidy for homes
Homes get a fixed subsidy, credited to the bank account after commissioning. Shops and industry are not covered by this scheme.
| Home system size | PM Surya Ghar subsidy |
|---|---|
| 1 kW | ₹30,000 |
| 2 kW | ₹60,000 |
| 3 kW and above | ₹78,000 |
Rules can change. We confirm the current amount for you.
How the calculator works
1. Units from your bill
We divide your bill by your tariff to find monthly units. If you enter units, we use those directly.
2. Size the system
Each kW makes about 120 units a month, so we match the size to your use. Each kW needs 2 panels and each panel takes about 30 sq ft, so roof area is about 60 sq ft per kW.
3. Savings and payback
We assume about 90% of your bill is offset, add your yearly tariff rise and a small panel ageing loss, then find when savings repay the cost.