Shadow Predictor

What it does

Calculates where a shadow will fall and roughly how long it will be, purely from the sun's calculated position at your location and the current time — no weather data is involved in this part, since shadow geometry only depends on where the sun is in the sky. For cloud cover and conditions, it links out to an external weather provider rather than fetching or displaying that data itself.

What you'll need

• Your location — either tap “Use my location” or enter latitude/longitude manually.

Steps

1. Set your location.
2. Read the shadow direction and length for right now.
3. Tap through to the external link if you also want to check cloud cover.

Reading the result

Shadow direction is given as a compass bearing (shadows fall directly opposite the sun). Shadow length is expressed as a multiple of subject height — e.g. 2.5× means a 2m subject casts a 5m shadow. Near sunrise/sunset this ratio grows very large; near midday it shrinks toward its minimum for the day.

Tips

• This updates live as you leave the page open, since the sun's position keeps changing.
• Combine this with the Golden & Blue Hour Countdown and Sun & Moon Compass tools for a fuller picture of the light at your location.

How is shadow direction and length calculated?

A shadow always falls directly opposite the sun — if the sun sits at a compass bearing of 90° (due east), the shadow points to 270° (due west), exactly 180° apart. Its length relative to the subject's height depends purely on how high the sun sits: the lower the sun, the longer the shadow, following simple trigonometry (length = height ÷ tan(sun's elevation)). This tool works out both numbers directly from the sun's calculated position for your location and the current time.

Why photographers use it

Shadow direction and length are easy to misjudge from memory — a subject's shadow can stretch dramatically across a beach at low sun, or a fence's pattern-shadows can land nowhere near where you pictured them. Working it out before you're on location, rather than showing up and hoping the light cooperates, is what this calculates directly from the sun's position.

Common mistakes

• Treating this as a weather forecast. it's pure sun-position geometry — clouds blocking the sun mean no shadow at all, regardless of what the tool predicts. Pair it with an actual cloud-cover check, which is why this page links out to a weather provider rather than guessing at conditions itself.
• Assuming shadow length scales evenly as the sun drops. it doesn't — length follows a tangent curve, growing slowly while the sun is high and then very steeply as it nears the horizon. A sun at 10° elevation casts a shadow about 5.7× subject height; at 5° elevation, over 11×. The change in the last few minutes before sunset is much bigger than it looks a little earlier.
• Ignoring uneven ground. the length ratio assumes a flat surface. A shadow falling across a slope, into a valley, or onto water will look noticeably different from the flat-ground prediction.
• Mixing up sun direction and shadow direction. the two are opposite by definition, 180° apart. Double-check which one you actually need — the direction shown here is where the shadow falls, not where the sun is.
• Not rechecking as a shoot goes on. both direction and length change continuously as the sun moves, sometimes fast in the hour around sunrise or sunset. A plan made 30 minutes before shooting can already be noticeably off by the time you're set up.

Example settings

FAQ

Why does the tool say "no shadow right now"?

The sun is below the horizon at your location — either nighttime, or before sunrise/after sunset. No sun above the horizon means no sun-cast shadow to predict.

Does this account for clouds?

No — it's pure sun-position geometry, calculated the same way regardless of sky conditions. Use the linked weather forecast alongside it to check actual cloud cover.

Why does shadow length change so fast near sunrise and sunset?

Because length follows 1 ÷ tan(elevation), a curve that grows very steeply as elevation approaches 0°. The last few degrees of the sun's descent toward the horizon stretch shadows far more than the same few degrees do earlier in the day.

Is my location sent anywhere to calculate this?

No — everything is computed entirely on your device from your coordinates. Nothing is sent to our servers or anywhere else.

Can I use this for indoor or artificial lighting?

No — it only models the sun's actual position based on your geographic coordinates and the current time. Artificial or studio lighting isn't tied to that and needs a different approach, like measuring the light's actual angle directly.