Correctly sizing a solar system avoids two expensive mistakes: undersizing (system doesn't cover your consumption) and oversizing (you pay for generation you can't use or export). This calculator determines the right kW system for your home based on your monthly electricity consumption.
How to use: Enter your monthly electricity consumption in kWh — this is the 'Units Consumed' figure on your DISCO bill. For hybrid systems with battery, tick the battery backup option to see the battery bank size recommendation alongside the panel system size.
Enter your monthly electricity consumption to find the right solar system size for your home or business.
Assumes 4.5 peak sun hours/day and 20% system losses. For battery sizing, assumes 8 hours of backup at 50% of daytime load.
How to Use Your Result
The recommended kW size is your target system capacity. When getting vendor quotes, ensure the quoted system is within 10% of this figure — significantly smaller means your bill reduction will be proportionally less; significantly larger means you're paying for excess capacity. The panel count assumes 545W panels, which are the current standard in Pakistan's market.
Frequently Asked Questions
Size for your annual average consumption — not your peak summer month. A system sized for peak summer will significantly overproduce in winter when consumption drops. The excess production is either lost (on-grid without net metering) or stored in batteries that may not discharge fully.
Use the 12-month average from your DISCO bill history. Most DISCO portals show consumption for the last 12 months. Sum the 12 months and divide by 12 for a reliable average that accounts for seasonal variation.
Yes, but it's significantly more expensive to expand later than to install the right size upfront. Expansion requires another installation visit, possibly a larger inverter, and additional mounting structure. Add a 15–20% buffer if you expect to add appliances within 3 years.