Solar Panel Angle & Tilt Calculator

The best tilt for your latitude, which direction to point the panels, and where the sun actually is right now — elevation, azimuth, sunrise and sunset. The formulas are public-domain astronomy and they're printed right on this page.

Your location
North positive, South negative. From any map or "my latitude" search. Tip: it's all that matters — see the zip-code FAQ.
Optimal fixed tilt
Direction to face (azimuth)
East positive, West negative. Only used for the compass bearing.
Where is the sun? (date & time)
For accurate clock times.
e.g. New York −5, London 0, New Delhi +5.5, Sydney +10. Standard time (no daylight-saving offset).

Geometry from public-domain astronomy (Cooper declination + NOAA solar-position equations), accurate to about a degree and a minute or two — plenty for siting panels. Estimates only, not a substitute for a professional site survey; real output also depends on shading, weather and roof structure.

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Turn the angle into energy Feed your tilt and direction into the Solar Panel Calculator to estimate how many kWh the array will produce. Building an off-grid system with batteries? Size the whole thing with the Off-Grid Solar Calculator.

Best solar panel tilt angle by latitude

Tilt is measured from horizontal: 0° is flat on the ground, 90° is straight up. The sun rides high in summer and low in winter, so the angle that keeps a fixed panel most square to the sun across the year turns out to be close to your latitude. That is the whole rule, and it is remarkably good — a fixed tilt equal to latitude, facing the equator, captures roughly 95% or more of the theoretical maximum annual energy.

The widely used rules of thumb (and these are rules of thumb, not exact optimisations):

Adjusting two or four times a year squeezes out a bit more — typically a few percent up to 10–25% at high latitudes where the seasonal sun swing is largest. The table below is computed from these rules for a range of latitudes; it is not copied from anywhere. Sort by reading down the latitude column to find the closest row to your site, whether you are working out a pv panel tilt angle in the US, a tilt angle in India, or anywhere else.

Optimal solar panel tilt angle by latitude (computed from the latitude rules above). Year-round ≈ latitude; summer ≈ lat − 15°; winter ≈ lat + 15°.
Latitude Year-round Summer Winter Example places

Method: public-domain physics. Year-round tilt = latitude; summer = max(0, latitude − 15°); winter = min(90, latitude + 15°). Examples are illustrative, not exhaustive.

Which direction should solar panels face? (azimuth & orientation)

Tilt only pays off if the panels also point the right way. The orientation, or azimuth, is the compass direction the panel faces, measured from true north. The rule is short: in the Northern Hemisphere face true south (180°); in the Southern Hemisphere face true north (0° / 360°). South-facing panels in the north see the sun across the whole productive midday window and out-produce east- or west-facing panels at the same tilt by roughly 10–25% a year.

The catch is that a compass does not point at true south — it points at magnetic north, which differs from true north by the magnetic declination at your location (east is positive, west negative). To get the compass bearing you would actually sight, subtract the declination from the true bearing. The direction section above does this for you: pick "compass bearing", enter your declination, and it reports both the true and magnetic figures so a solar panel direction-and-angle plan turns into something you can set with a real compass.

Where is the sun? Sun position calculator

Everything above comes from one thing: where the sun is in your sky. This solar position calculator takes your latitude, a date and a time and returns the sun's elevation (its altitude angle above the horizon) and its azimuth (compass direction), plus sunrise, sunset and solar noon. It is a genuine solar azimuth angle calculator and sun altitude/elevation angle calculator in one, useful for checking when a tree or roofline will shade the array and for understanding why the seasonal tilts above work.

The sun-path diagram above the article plots the sun's track across the sky for your chosen date, with the current time marked, so calculating the sun angle becomes something you can see rather than just read. At solar noon the sun is due south (north of the equator) at its highest elevation of the day; that noon elevation is exactly what the tilt rules are chasing.

The formulas

No black boxes. These are the standard equations — Cooper's declination plus the NOAA solar-position set — that every solar elevation, azimuth and tilt-angle formula is built on. Angles in degrees; convert to radians for the trig.

n = day of the year (1–365)
Declination (Cooper): δ = 23.45° × sin( 360°/365 × (284 + n) )

Equation of time: B = 360°/364 × (n − 81)
EoT = 9.87·sin(2B) − 7.53·cos(B) − 1.5·sin(B) (minutes)
Solar time = clock + ( 4·(longitude − 15·timezone) + EoT ) / 60 (hours)

Hour angle: H = 15° × (solar time − 12)

Elevation / altitude:
sin(α) = sin(φ)·sin(δ) + cos(φ)·cos(δ)·cos(H)

Azimuth (from true north, clockwise):
Az = atan2( sin(H), cos(H)·sin(φ) − tan(δ)·cos(φ) )
Az = ( Az + 180° ) mod 360°

Sunrise / sunset hour angle:
cos(H₀) = −tan(φ)·tan(δ)
daylight hours = 2·H₀ / 15 ; sunrise = 12 − H₀/15 ; sunset = 12 + H₀/15 (solar time)

For an azimuth example: in Miami (about 25.8° N) on 1 August at 10:00 solar time the declination is roughly +17.9°, the hour angle is −30°, and the equations give an elevation near 61° and an azimuth near 100° (just south of due east) — exactly where you'd expect the late-morning summer sun. Run your own numbers in the section above.

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Frequently asked questions

What's the optimal angle for solar panels?

For a fixed installation, set the tilt equal to your latitude. At 40° latitude (New York, Madrid) tilt the panels to about 40° from horizontal. This latitude rule captures roughly 95% or more of the theoretical maximum annual energy for a panel facing the equator, so exact precision isn't critical for most rooftops.

Which way should solar panels face?

In the Northern Hemisphere face true south (180° azimuth); in the Southern Hemisphere face true north (0°/360°). True south isn't magnetic south — a compass points to magnetic north, offset by your local magnetic declination (east positive, west negative). Enter your declination above and the calculator converts the true bearing to the compass bearing you'd actually read.

What tilt for winter vs summer?

Set the tilt steeper in winter to catch the low sun (about latitude + 15°) and shallower in summer (about latitude − 15°); year-round, use roughly your latitude (sometimes latitude × 0.9). The sun's declination swings ±23.45° over the year, so a steeper winter tilt keeps the panel square to the low midday sun and a flatter summer tilt does the same when the sun is high.

How do I find the sun's elevation angle?

Elevation (altitude) is sin(elevation) = sin(latitude)·sin(declination) + cos(latitude)·cos(declination)·cos(hour angle). Declination comes from the day of the year and the hour angle is 15° per hour from solar noon. Enter your latitude, date and time in the sun-position section and the calculator returns elevation and azimuth plus sunrise, sunset and solar noon.

Best solar panel angle for India?

India spans roughly 8°–35° N, so the optimal fixed tilt runs from about 8–13° in the far south (Chennai, Bengaluru) to about 28–32° in the north (New Delhi), facing true south. A common practical compromise is around 10–15° in the south and 20–30° in the north. Enter your city's latitude above for an exact figure.

Does angle by zip code matter (or just latitude)?

The optimal tilt and the sun's position depend almost entirely on latitude, not the full zip code. Two places at the same latitude have nearly identical optimal tilt and sun geometry. A zip code only matters because it pins down your latitude (and longitude, which shifts clock times); local climate and shading affect production but not the geometric best angle. Enter your latitude and you have the answer.