Solar Geometry
Panel Tilt & Azimuth Optimiser
Find the best fixed tilt angle and facing direction
Updated 12 July 2026 · Live
What this tool does
Suggests the optimal fixed tilt angle and azimuth for a solar array from your latitude, season priority and hemisphere.
Enter your latitude, the season you want to favour and your hemisphere; the calculator returns the optimal fixed tilt angle and the direction to face.
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Formula Used
How the panel tilt & azimuth works
For a fixed array the best year-round tilt is roughly equal to the site latitude. Tilting about 15° shallower favours the high summer sun; tilting about 15° steeper favours the low winter sun and helps shed snow. In the northern hemisphere the array faces true south; in the southern hemisphere it faces true north. The tilt is clamped between flat and vertical.
What you enter
Enter your latitude, the season you want to favour and your hemisphere; the calculator returns the optimal fixed tilt angle and the direction to face. Every field is editable, and the result recalculates the moment you change a value.
Reading the result
The tilt and azimuth are a strong starting point for a fixed roof or ground mount. A few degrees either side changes annual yield only slightly, so match the nearest convenient roof pitch where practical.
Safe by design
This calculator does the arithmetic of sizing — quantities, geometry and cost. It deliberately stops at the line a certified installer must sign off. It will never tell you a cable or fuse size, an earthing arrangement, a battery charge voltage, or a roof structural load: those are regulated calculations where a wrong number causes fire, electrocution or collapse. All electrical work must be carried out by a qualified, certified installer, and this page is not an installation guide.
Assumptions and limits
This is a fixed-tilt rule of thumb, not a tracker or shading model. It assumes an unobstructed horizon; real yield depends on shading, roof pitch and orientation you cannot always change. Magnetic compass readings need correcting to true north or south for the azimuth to hold.
Using it with the rest of BuildMetricLab
This calculator is one step in planning a system. Pair it with the other solar sizing, geometry and cost tools to go from an energy figure to a panel count, a layout and a costed bill of materials. Every BuildMetricLab tool runs entirely in your browser — no sign-up, nothing sent to a server, and the formula is shown on the page so the maths can be audited.
Sources & methodology
Suggests the optimal fixed tilt angle and azimuth for a solar array from your latitude, season priority and hemisphere. Every result is calculated from the values you enter, all inputs are editable, and no time-sensitive prices or tariffs are embedded.
Frequently asked questions
Why is the ideal tilt close to my latitude?
At a tilt equal to latitude the array faces the sun’s average path over the year, which maximises the annual total for a fixed mount.
Should I steepen the angle for winter?
A steeper tilt of roughly latitude plus 15° catches the low winter sun more squarely and helps snow slide off, at the cost of some summer yield.
What azimuth is best?
True south in the northern hemisphere and true north in the southern hemisphere. Correct a compass bearing for local magnetic declination to find true north.
Does a small angle error matter?
Not much. Within about 10–15° of ideal the annual loss is small, so matching an existing roof pitch is usually fine.
Spotted something off?
Calculations or display — let us know.