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Solar System Calculator Pakistan (Size & Payback)
Free solar calculator for Pakistan: the system size in kW for your monthly units, number of panels, roof space, cost, monthly saving and payback, including the new net billing rules for users from February 2026.
System size you need
3.5 kW
💡 Before you buy
- Since 9 February 2026 new solar users get net billing: the grid pays a lower price for exported units than you pay for imported ones, so using your own solar during the day (or a battery) saves the most.
- Users with net metering agreements signed before that date keep their old terms.
- Get a written quote with panel brand, inverter, structure and warranty. Tier-1 panels usually come with a 25-year performance warranty.
Estimates only: real output depends on shade, dust, roof angle and the season. 🔒 Calculated on your device.
📚 Official sources: NEPRA
We build every tool from the official rules and re-check them when they change. Always confirm with the official source before you rely on a result.
🛠️ Spotted a mistake or an out-of-date rule? Tell us
Questions people ask
What size solar system do I need for 450 units?+
About 3.5 kW at 4.5 sun hours a day: 450 ÷ 30 ÷ 4.5 = 3.3 kW, rounded up.
Is net metering still available?+
For new users, NEPRA replaced it with net billing from 9 February 2026: exported units are bought at a lower rate than you pay. Existing agreements keep their terms.