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Updated July 2026

Solar Calculation Guides

Learn the maths behind every calculator on this site: sizing formulas, output calculations, city-wise tilt angles, complete home system design and off-grid planning, all with worked Indian examples.

Solar Panel Calculation Formula Every formula in one place: system size, panels, output, roof area, cost, subsidy, battery and EMI, with worked examples. How to Calculate Solar Panel Output Step-by-step kWh calculation from peak sun hours, the 0.8 performance ratio and the losses inside it. Solar Panel Tilt Angle in India Optimum tilt for 30+ cities, seasonal winter and summer angles, direction and mounting rules. Calculate a Solar System for Your Home From bill to units to kW, panels, roof, cost and subsidy, one worked example end to end. Off Grid Solar System Calculation Load, battery bank, panel array, inverter and wiring for a home with no grid support.

How These Guides Fit Together

Start with the calculation formula guide if you want the full reference sheet, or jump straight to the question you have: the home system guide walks a complete purchase decision from a single electricity bill, the output guide explains what your panels will really generate, the tilt angle guide covers mounting, and the off-grid guide handles homes without grid support.

Every guide pairs with live tools that do the maths for you: browse them by category under sizing and design, cost and finance, generation and output and battery and backup, or run the all-in-one solar calculator for India on the homepage.

Solar Guides: Frequently Asked Questions

Do I need to read the guides before using the calculators?+
No. Every calculator works on its own with plain inputs. The guides are for people who want to understand or verify the maths, check an installer's claims, or do the calculations by hand.
Are the formulas in these guides India-specific?+
The physics is universal, but every constant is Indian: city peak sun hours, ₹ per kW price bands, subsidy slabs, DISCOM tariffs and 80 to 100 sq. ft. per kW roof norms. Examples use real Indian cities throughout.
Will more guides be added?+
Yes, the guide library grows alongside the tools. If a topic you need is missing, suggest it through the contact page and we will consider it for the roadmap.

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