Enter your monthly electricity bill and get an instant estimate of your rooftop system size, number of panels, roof area, installation cost, government subsidy, and yearly savings. Built for Bangalore, Hubballi–Dharwad, and the rest of Karnataka.
Homes are eligible for the PM Surya Ghar rooftop subsidy.
Grid-connected, no battery. The usual choice for a stable supply.
The calculator works backwards from your electricity use. Here is the logic in plain terms:
You only need your bill to get an estimate. The rest fine-tunes it.
A quick reference for on-grid residential rooftop systems. Costs are indicative and before subsidy.
| System | Panels | Roof area | Generation | Cost before subsidy |
|---|---|---|---|---|
| 1 kW | 2 | 100 sq ft | ~120 units/mo | ₹55,000 – ₹65,000 |
| 2 kW | 4 | 200 sq ft | ~240 units/mo | ₹1.1 – 1.3 lakh |
| 3 kW | 6 | 300 sq ft | ~360 units/mo | ₹1.6 – 1.9 lakh |
| 5 kW | 10 | 500 sq ft | ~600 units/mo | ₹2.4 – 2.8 lakh |
| 10 kW | 19 | 1,000 sq ft | ~1,200 units/mo | ₹4.8 – 5.6 lakh |
It gives a close ballpark for planning. The size and generation estimates use standard assumptions for Karnataka. The final numbers depend on your actual roof, shading through the day, panel and inverter choice, and your DISCOM tariff, which we confirm during a site survey.
Most homes need between 4 and 12 panels. A 550 W panel produces roughly 65–75 units a month in Karnataka, so a family with a ₹3,000–4,000 bill usually lands on a 3 to 3.5 kW system, which is about 6 to 7 panels.
A 3 kW on-grid rooftop system in Bangalore is typically ₹1.6–1.9 lakh before subsidy. After the PM Surya Ghar residential subsidy of ₹78,000, the net cost comes down to roughly ₹85,000–1.15 lakh. The final figure depends on the roof type, the panel and inverter brand, and the mounting structure needed.
Allow about 100 sq ft of shadow-free roof per kW. So a 3 kW system needs around 300 sq ft and a 5 kW system around 500 sq ft. Metal-sheet roofs can be a little tighter; RCC roofs need walkway space.
The PM Surya Ghar subsidy is available for residential rooftop systems, and Paso Solar files the application for you. The approval, the amount, and the eligibility are decided by the authority, and the scheme rules can change, so we confirm what applies to you before you commit.
Even after solar covers all your units, your bill keeps a monthly fixed charge based on your sanctioned load, plus any minimum charge and meter rent. Solar offsets the energy part of the bill, which is usually most of it, but not the fixed part. The calculator accounts for this, so the savings it shows are what you can realistically expect.
We divide the net cost, after subsidy, by the estimated yearly savings on your bill. Most residential systems in Karnataka pay back in about 3 to 5 years and then keep generating for 20 years or more.
Share your latest bill and roof details. Our team confirms the exact system size, cost, and subsidy for your property, usually the same working day.