Solar Panel Size Calculator India 2026

Find out exactly how many solar panels you need for your home or business. Choose your panel wattage, enter your monthly consumption, and get an instant count with roof area and cost estimates.

Popular Solar Panel Wattages in India 2026

Panel TypeWattageDimensions (approx)Area/PanelBest For
Mono PERC Popular400W1755 × 1038 mm~20 sq ftHomes, SME
Mono PERC440W1903 × 1040 mm~22 sq ftHomes, SME
TOPCon Premium480W2094 × 1038 mm~24 sq ftHomes, Commercial
TOPCon / HJT540W2256 × 1133 mm~28 sq ftCommercial rooftop
Bifacial TOPCon600W2384 × 1134 mm~30 sq ftLarge commercial

How Many Panels Do You Need? — The Formula

The number of panels depends on three things: how much electricity you use, how much your city's sun can generate per panel, and how much of your bill you want to offset.

Daily Generation per Panel = Wattage (kW) × Peak Sun Hours
Monthly Generation per Panel = Daily × 30 days
Panels Needed = Monthly Consumption ÷ Monthly Generation per Panel

Example: 400W panels in Delhi (5 peak sun hours/day):
Daily gen = 0.4 kW × 5 hrs = 2 units/day → 60 units/month per panel.
For 300 units/month: 300 ÷ 60 = 5 panels needed.

Mono PERC vs TOPCon — What to Choose?

Mono PERC (400–440W): Most widely installed in India. Cost-effective, reliable, backed by many local manufacturers (Waaree, Vikram, Adani Solar, Tata Power Solar). Ideal for most homes and small businesses.

TOPCon (450–550W): 2–3% higher efficiency than Mono PERC. Better performance in low light and high temperatures — important in Indian summers where panel temps can hit 60–70°C. Premium price but delivers more units/sq ft of roof.

HJT (Heterojunction): Best in class for efficiency and temperature coefficient. Significantly more expensive. Suited for premium installations with space constraints.

☀️ Pro tip: If your roof space is tight (under 200 sq ft for a 3 kW system), choose higher-wattage TOPCon panels to fit more power in less area. If space is not a constraint, standard 400W Mono PERC panels give the best value for money.

Roof Area Planning

Each panel needs its physical area plus spacing for mounting rails and walkway access. A practical rule of thumb is 22–25 sq ft per panel (including gaps) for a standard ground-mounted or rooftop installation.

Avoid areas with shade from water tanks, chimneys, AC units, or adjacent buildings. Even 10% shading on a panel can reduce system output by 20–30% if you don't have micro-inverters or power optimisers.

Top Indian Solar Panel Brands 2026

Waaree Energies — India's largest panel manufacturer. Wide range, good warranty support.

Vikram Solar — Premium brand, strong export market. Good efficiency ratings.

Adani Solar — Vertically integrated, competitive pricing for large volumes.

Tata Power Solar — Trusted brand, strong service network across India.

Saatvik Solar — Growing manufacturer, good value for residential.

Frequently Asked Questions

For 300 units/month in Delhi (5 peak sun hours/day) with 400W panels: each panel produces ~60 units/month. You need 300 ÷ 60 = 5 panels (2 kW system). In Jaipur (5.5 hrs), you may need only 4–5 panels. In Kolkata (4.5 hrs), you may need 6 panels.
A standard 400W Mono PERC panel measures approximately 1755mm × 1038mm (about 6 ft × 3.5 ft) and weighs 20–22 kg. It covers roughly 20 sq ft. With mounting gaps, plan 22–25 sq ft of roof area per panel.
400W–440W Mono PERC panels are the most popular for Indian homes in 2026. They balance efficiency, cost, and warranty. TOPCon 480–540W panels are better if you have limited roof space or want higher output per panel. HJT panels cost more and suit premium, space-constrained installs.
A 400W panel needs ~20 sq ft (1.82 sq metres) of physical space. With mounting hardware clearance and row spacing, plan ~22–25 sq ft per panel. For 10 panels: ~220–250 sq ft of shadow-free roof area. Always deduct space occupied by water tanks, AC outdoor units, and chimneys.
A typical 2BHK flat terrace in India offers 400–600 sq ft, but after deducting obstacles and clearances, 250–400 sq ft is usable. That fits 10–16 panels (400W) = 4–6.4 kW system. For a 3 kW system you need ~200 sq ft of clear roof — achievable on most independent homes.
Yes, up to your consumption level. Beyond 100% coverage, extra panels generate surplus electricity that must be exported via net metering (earning ₹2–5/unit depending on state). So oversizing is still useful if you have net metering — you earn additional income from exports instead of paying for grid power.

🔆 Solar Panel Count Calculator

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