SunCalc alternative with 3D buildings

SunCalc.org gives you the sun's position, the day's sun times and the shadow of a single object at a height you type in. Sundial works out the same sun positions but draws the shadow of every building around an address in 3D, and adds a map of sun hours for the day. Both are free.

Sundial is free, with no sign-up. SunCalc.org details checked on its own site and app listing in October 2026.

One thing to clear up first. Sundial's sun positions come from the open-source SunCalc JavaScript library. That library is a separate project from the SunCalc.org website, which is what this page compares against.

What SunCalc.org does well

SunCalc.org, run by Torsten Hoffmann in Germany, is a data-rich sun calculator on a flat map. Drop a pin and it shows the day's sun path as a thin yellow curve, with a shaded band for how the path shifts through the year. Alongside it you get dawn, sunrise, culmination, sunset, dusk, daylight duration, and the sun's altitude and azimuth.

It has a few tools Sundial doesn't. A reverse calculation finds when the sun will reach a given altitude and azimuth. A photovoltaic panel lists air mass and clear-sky irradiance. You can set the year anywhere from 1500 BC to AD 3000, and the page includes solar eclipse data. Sister sites cover the moon (MoonCalc) and the planets (PlanetsCalc).

The shadow figure is for one object at a time: enter a height in metres and it gives that object's shadow length. Links carry the position, date, time, object height and map type, as set out in its linking guide. The website is free and asks for donations, and there is a free SunCalc org Android app with more than 500,000 downloads.

Where Sundial is different

Sundial starts from the buildings. It loads footprints and heights from OpenStreetMap for 300 m around the address, draws them in 3D, and casts every shadow from where the sun actually is at that minute. You don't need to know how tall the building next door is, or which way its shadow points. You can see it on the ground.

The sun's arc for the day is drawn over the rooftops in 3D, together with the June and December solstice arcs and a compass. The Sun hours view colours every patch of ground and roof by its hours of direct sun that day. The date and time sliders snap to the equinoxes, solstices, sunrise, solar noon and sunset.

The same sums, shown two ways

At Piccadilly Gardens in Manchester on 23 September, solar noon is at 13:02 and the sun is 36.5° above the horizon. SunCalc.org will tell you a 1 m post casts a 1.35 m shadow, and a 20 m office block about 27 m. That's useful if you already know which block you're worried about. Sundial shows all the surrounding blocks at once, so you can see which part of the gardens their shadows reach.

SunCalc.org sources: suncalc.org, SunCalc.org linking guide, Google Play listing. Checked October 2026.

Which one to use

Use SunCalc.org when you want numbers: dawn and dusk times, the shadow of a mast or a pole, the time the sun hits a certain bearing, solar panel inputs, or a date centuries away. It puts a lot of data on one screen.

Use Sundial when the question is about a real place with buildings around it, such as whether a terrace keeps the sun at 5 pm in April or which end of a garden stays bright in winter. Open the sun path map, search the address, and drag the clock. For the angle maths itself, see the sun angle calculator guide.