TopToolAISolar Calculator
Estimate the solar system size, installation cost and monthly savings for your home, based on your average electricity usage, local sun hours, and installation price per kW. A home using 600 units a month in an area with 5 peak sun hours a day typically needs around a 4kW system, which at roughly PKR 180,000 per kW installed comes to about PKR 720,000 upfront, often paid back within 4-6 years through lower electricity bills.
How to use Solar Calculator
Step-by-step guide to the boxes below. Open it only if you need help.
How to use Solar Calculator
Step-by-step guide to the boxes below. Open it only if you need help.
-
1
Average monthly units (kWh) Number
Check a recent electricity bill and enter the units used per month.
Example: 800
-
2
Peak sun hours/day Number
The hours of strong sunlight your area gets daily. If you do not know, keep 5.
Example: 5
-
3
System efficiency (0–1) Number
Real-world efficiency after losses. 0.8 means 80% and is a sensible default.
Example: 0.8
-
4
Price per kW installed (Rs) Number
The local price of installing one kW of solar, including panels and fitting. Ask two or three installers.
Example: 150000
-
5
Rate per unit (Rs) Number
What your utility charges per unit now. It is on your bill.
Example: 45
-
6
Press “Calculate”
Click the button under the boxes. If something is missing or not valid, a short message tells you which box to fix.
-
7
Read your result
You see the solar system size you need, its cost and how long it takes to pay itself back. Change any box and try again to compare different numbers.
Solar Calculator FAQs
User Reviews
No reviews yet — be the first to try this tool and leave one.
More Free Tools
Handy the next time you're here
Leave a review