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Both calculators run independently — change the inputs on either side to compare results.
Solar Panel Angle Optimizer Calculator
Find the optimal tilt and orientation for your solar panels to maximize annual energy output based on your latitude and roof direction. Ideal for homeowners and installers planning new solar installations.
Solar Panel System Sizing Calculator
Calculate exactly how many solar panels your home needs based on your electricity bill, local sun exposure, panel wattage, and desired offset. Ideal for homeowners planning a rooftop PV installation.
Solar panels needed
21 panels
9.33: 7-10 W per monthly kWh is the normal range for a 100% offset at 4.5-5.5 sun hours. The example (9.3 W/kWh: 21x400W panels for 900 kWh) sits here.
This is installed watts per kWh of monthly usage; the formula's own math ties panel count to your offset target, sun hours, and losses, with ~7-13 W per monthly kWh being typical.
Key differences
| Solar Panel Angle Optimizer Calculator | Solar Panel System Sizing Calculator | |
|---|---|---|
| Category | Solar Energy | Solar Energy |
| Inputs required | 3 | 5 |
| Result | Annual Energy Production (kWh) | Solar panels needed (panels) |
| What it does | Find the optimal tilt and orientation for your solar panels to maximize annual energy output based on your latitude and roof direction. Ideal for homeowners and installers planning new solar installations. | Calculate exactly how many solar panels your home needs based on your electricity bill, local sun exposure, panel wattage, and desired offset. Ideal for homeowners planning a rooftop PV installation. |