Design Tool

Tilt & Orientation Yield Estimator

Get an indicative annual-yield figure for a roof from its direction and pitch, relative to an optimally-oriented array.

Evidence-first · every figure sourcedReviewed July 2026Our methodology

Key takeaways

Gives an indicative annual-yield figure for a roof from its direction and pitch.
Compares your roof to an optimally-oriented array, expressed as a relative yield percentage.
Adds a rating and guidance so you can read the result at a glance.

Roof direction the panels faceIn the southern hemisphere, north faces the sun.Roof pitch (tilt)°Most Australian roofs are 15–25°. Optimal ≈ your latitude.

Indicative yield

99%

Rating

Excellent

Relative to an optimally-oriented array (north, ~latitude tilt = 100%). Indicative only — real yield depends on your exact location, shading and weather.

How it works

This gives an indicative annual yield relative to an optimally-oriented array (true north, tilt near your latitude = 100%). It multiplies two factors:

Direction. In the southern hemisphere north is best; east- or west-facing roofs typically give up around 15%, and south-facing considerably more.
Pitch. Output peaks near a tilt of roughly your latitude (about 20–30° for most of Australia). A dead-flat roof loses roughly 10%, and very steep pitches taper off too.

These factors are rules of thumb drawn from Australian orientation data — useful for a quick read, but real yield depends on your exact location, shading and weather. For precise numbers use a tool like NREL's PVWatts or ask your installer, and see our orientation field guide for the why behind the numbers. East/west splits also smooth output across the day, which can lift self-consumption even at a slightly lower total.

Estimates only — for guidance, not a quote or engineering specification. Nothing you enter is stored or sent anywhere; the maths runs entirely in your browser.

Good to know

Frequently asked

Is this tool free to use?: Yes. The tilt and orientation estimator is free and needs no sign-up. It runs entirely in your browser.
Is my data stored or sent anywhere?: No. The tool runs in your browser and stores nothing. The figures you enter are not saved or sent anywhere.
What does the relative yield percentage mean?: It is an indicative comparison of your roof's direction and pitch against an optimally-oriented array. The figure is an estimate, not a measured output.

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This gives an indicative annual yield relative to an optimally-oriented array (true north, tilt near your latitude = 100%). It multiplies two factors:

Direction. In the southern hemisphere north is best; east- or west-facing roofs typically give up around 15%, and south-facing considerably more.
Pitch. Output peaks near a tilt of roughly your latitude (about 20–30° for most of Australia). A dead-flat roof loses roughly 10%, and very steep pitches taper off too.

Frequently asked

Is this tool free to use?

Yes. The tilt and orientation estimator is free and needs no sign-up. It runs entirely in your browser.

Is my data stored or sent anywhere?

No. The tool runs in your browser and stores nothing. The figures you enter are not saved or sent anywhere.

What does the relative yield percentage mean?

It is an indicative comparison of your roof's direction and pitch against an optimally-oriented array. The figure is an estimate, not a measured output.