Bar: share of direct sunlight that strikes the panel face at this moment (cosine of the angle of incidence).
Never look directly at the sun, even briefly, and never through binoculars, a camera or a telescope.
Formula and breakdown
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This sun position calculator gives the sun’s elevation and compass direction for any date, clock time and place, plus sunrise, solar noon, sunset and the angle at which sunlight strikes a solar panel. It is set up for the UK, Ireland and the rest of Europe, with summer time applied automatically for the city presets, and works anywhere with a custom latitude, longitude and UTC offset.
Quick answer: A sun position calculator turns a date, clock time, UTC offset, latitude and longitude into the sun’s elevation above the horizon and its azimuth clockwise from north. On 21 June 2026 at 13:00 BST in London the sun stands 61.93° high at 178.86°, almost due south, using the NOAA equations with refraction.
What Is a Sun Position Calculator?
A sun position calculator is a tool that computes where the sun appears in the sky, as an elevation angle above the horizon and an azimuth angle clockwise from north, for a given place and moment. The formula in plain words: convert the clock time to universal time and a Julian day; from that, find the sun’s declination and the equation of time; correct clock time to true solar time using your longitude; turn true solar time into an hour angle; then combine latitude, declination and hour angle with spherical trigonometry to get the zenith angle and azimuth, and add atmospheric refraction.
The sun position calculator uses the equations behind the NOAA Solar Calculator, which NOAA says are based on Astronomical Algorithms by Jean Meeus and are suitable for dates from 1901 to 2099 in its spreadsheet form. You can read the method on the NOAA calculation details page. Every step appears in the breakdown under the result.
How Do You Use the Sun Position Calculator?
- Choose a city, or pick custom and type your latitude and longitude in decimal degrees. West of Greenwich and south of the equator are negative.
- Set the date and the local clock time. Seconds are allowed.
- Check the UTC offset. For city presets it switches to summer time automatically; for custom places enter it yourself.
- Optionally enter the tilt and facing of a solar panel.
- Read the elevation and azimuth, then the sunrise, noon and sunset times, shadow length and the sun angle on your panel. Use current time fills in the moment you are looking at the page.
How High Does the Sun Get in the UK and Europe?
At noon the sun’s elevation is roughly 90 degrees minus your latitude, plus the declination, which runs from about +23.44 degrees at the June solstice to about minus 23.44 degrees in December. London at 51.5 degrees north therefore sees a noon sun of about 62 degrees in June but only about 15 degrees in late December.
| City | Latitude | Noon elevation, June solstice | Noon elevation, equinoxes | Noon elevation, December solstice |
|---|---|---|---|---|
| Stockholm | 59.33° N | 54.1° | 30.7° | 7.2° |
| Edinburgh | 55.95° N | 57.5° | 34.0° | 10.6° |
| Dublin | 53.35° N | 60.1° | 36.6° | 13.2° |
| Berlin | 52.52° N | 60.9° | 37.5° | 14.0° |
| London | 51.51° N | 61.9° | 38.5° | 15.1° |
| Paris | 48.86° N | 64.6° | 41.1° | 17.7° |
| Rome | 41.90° N | 71.5° | 48.1° | 24.7° |
| Madrid | 40.42° N | 73.0° | 49.6° | 26.1° |
| Athens | 37.98° N | 75.5° | 52.0° | 28.6° |
Values are geometric noon elevations using a declination of 23.44 degrees; refraction adds a few hundredths of a degree at these heights. The low winter sun explains why panels in northern Europe produce so little in December and why a steeper tilt helps in winter, which you can test with the solar panel angle calculator.
Why Is Solar Noon Not at 12:00?
Solar noon, when the sun crosses due south in the northern hemisphere, falls at 12:00 only if you live exactly on your time zone’s reference meridian and the equation of time is zero. Each degree of longitude moves solar noon by 4 minutes, and the equation of time shifts it by up to about 16 minutes through the year because the earth’s orbit is elliptical and its axis is tilted. On top of that, summer time moves clocks forward an hour.
In the UK, clocks go forward at 1am on the last Sunday in March and back at 2am on the last Sunday in October, so solar noon in London is close to 12:00 GMT in winter and close to 13:00 BST in summer. EU countries switch on the same Sundays. The sun position calculator applies this for the city presets.
What Do Elevation, Azimuth and Zenith Mean?
Elevation is the sun’s height above the horizon, azimuth is its compass bearing clockwise from north, and the zenith angle is the angle from straight overhead, equal to 90 degrees minus the elevation.
- Elevation of 0 degrees means the sun’s centre is on a flat horizon; negative values mean it is below.
- Azimuth 90 degrees is east, 180 degrees is south and 270 degrees is west. The tool also gives a 16-point compass label.
- Declination is the latitude at which the sun is directly overhead at noon on that day.
- The hour angle is how far, in degrees, the sun is from solar noon; it changes by 15 degrees an hour.
How Accurate Is the Calculated Sun Position?
The NOAA equations are accurate enough for solar design and shading work: on a published high-precision test case they agree to within about a hundredth of a degree. We checked the tool against the published test case in NREL’s Solar Position Algorithm report: for 17 October 2003 at 12:30:30 local standard time (UTC minus 7) at latitude 39.742476 and longitude minus 105.1786, NREL gives a zenith angle of 50.11162 degrees and an azimuth of 194.34024 degrees. The calculator returns 50.11 degrees and 194.34 degrees.
Real conditions add small differences. Refraction near the horizon changes with air temperature and pressure, hills and buildings hide the sun before the calculated sunset, and NOAA notes that its spreadsheet method is valid from 1901 to 2099. For shading on a roof, combine the sun’s position with the height and distance of the obstacle.
How Does the Sun Angle Affect Solar Panels?
A panel collects the most direct sunlight when the sun is square on to its face, and the share it receives falls with the cosine of the angle of incidence: at 60 degrees off square, only half of the direct beam lands on the panel. The calculator works this out from the sun’s zenith and azimuth and your panel tilt and facing, which shows at a glance why east or west roofs peak in the morning or afternoon. For the effect on yearly output, use the solar panel orientation calculator.
Never look directly at the sun, even briefly, and never through binoculars, a camera viewfinder or a telescope.
Worked Example: London at Midsummer
Example: a homeowner in London wants to know where the sun is at 13:00 on 21 June 2026, and how squarely it hits a south-facing roof panel tilted at 35 degrees.
- London is at 51.51 degrees north and 0.13 degrees west. The date falls in British Summer Time, so the offset is +1 and 13:00 BST is 12:00 UTC.
- For that moment the declination is 23.4381 degrees and the equation of time is minus 1.82 minutes.
- True solar time = 780 + (minus 1.82) + 4 x (minus 0.13) minus 60 x 1 = 717.66 minutes, so the hour angle is 717.66 / 4 minus 180 = minus 0.59 degrees, just before solar noon.
- cos(zenith) = sin 51.51 x sin 23.4381 + cos 51.51 x cos 23.4381 x cos 0.59 = 0.8823, a geometric elevation of 61.92 degrees. Refraction adds about 0.01 degrees: 61.93 degrees.
- The azimuth is 178.86 degrees, just east of due south.
- On the panel, the sun is 6.95 degrees from square on, so 99% of the direct beam reaches the face.
Sunrise is at 04:43 BST, solar noon at 13:02 and sunset at 21:22, giving 16 hours 39 minutes of daylight.
Frequently Asked Questions
What is the difference between solar elevation and azimuth?
Elevation is the sun’s height above the horizon in degrees, from 0 at the horizon to 90 overhead. Azimuth is its compass direction measured clockwise from north, so 90 is east, 180 is south and 270 is west.
Why is solar noon not at 12:00?
Clock time follows a time zone, not your exact longitude, and the earth’s elliptical orbit and tilt make the sun run up to about 16 minutes fast or slow over the year. Summer time adds another hour, so UK solar noon is near 13:00 BST.
How accurate is this sun position calculator?
It uses the NOAA Solar Calculator equations based on Jean Meeus’s Astronomical Algorithms, valid for 1901 to 2099. On the NREL published test case it agrees with the reference zenith and azimuth to within 0.01 degree. Near the horizon, real refraction can differ from the standard value.
Does the calculator handle British Summer Time?
Yes. When you choose a UK or EU city, the tool applies summer time between the last Sunday in March and the last Sunday in October, so the offset becomes +1 in the UK. For other places, choose custom and enter the UTC offset.
How do I use the sun position for solar panels?
Enter your panel tilt and facing. The calculator gives the angle between the sun and a line square to the panel, and the share of direct sunlight that strikes the face. Low values show times when the panel catches little direct sun.
What does atmospheric refraction change?
Air bends sunlight, so the sun appears slightly higher than its true position. The effect is tiny when the sun is high but reaches about half a degree at the horizon, which is why sunrise and sunset use 90.833 degrees from the zenith.
Checked October 2026 by the Solaxyra Editorial Team. Sources: NOAA Solar Calculator details, NOAA solar position equations, NREL Solar Position Algorithm, GOV.UK clock changes, European Commission, summer time.