Roof Angle Optimizer
Find the best solar panel angle for your roof and the seasons
Roof angle output
The optimal angle changes by season — steeper catches more low winter sun, flatter is better for high summer sun. Scrub through the months to see.
Annual average
Annual at 35°
98%
3,407 kWh
Annual optimal (35°)
100%
3,474 kWh
Difference
-2%
At 35° your panels capture 98% of maximum annual output. The annual optimal is ~35° which balances summer and winter.
How this works
The optimal roof pitch for annual UK solar generation is 30-35 degrees. Most pitched UK roofs fall in the 25-45 degree range, so they are near-optimal without modification.
The best angle changes by season because the sun sits higher in summer and lower in winter. In December, the optimal pitch is around 62 degrees (steep). In June, it is 18 degrees (almost flat).
The calculator uses PVGis-based output factors for UK latitude (~52°N). Move the month slider to see how your specific roof pitch performs throughout the year.
Things to consider
- •Flat roofs can use tilted frames to angle panels optimally — this adds cost but significantly boosts output.
- •Solar tracking systems that follow the sun are rarely cost-effective in the UK — the extra output does not pay back the added complexity.
- •A less-than-ideal angle costs surprisingly little — even a vertical wall panel produces 37% of optimal, which is why balcony solar works.
- •Roof direction matters more than angle for most UK homes. A 45° east-facing roof beats a 20° south-facing one for many usage patterns.
Dig deeper
Roof Orientation and Solar: Direction Trade-Offs
How roof orientation affects solar panel performance in the UK. South, east, west, and north-facing roof output compared, plus split-orientation strategies.
Is My Roof Suitable for Solar Panels?
Find out if your roof can take solar panels — covering direction, angle, shading, structural condition, and options for tricky roofs.
Solar Panels on a Flat Roof: Mounting, Costs and Planning
Flat roof solar in the UK — ballasted vs frame-mounted systems, optimal tilt angle, planning permission, costs vs pitched roof, and pros and cons.
Wall-Mounted Solar Panels: A Viable Alternative?
Can you mount solar panels on a wall in the UK? When wall-mounted solar makes sense, how it performs, costs, and planning permission requirements.
Want this personalised to your home?
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