Shadow Length Calculator
Shadow length from sun altitude, or noon shadow from latitude and date
Shadow Length (enter sun altitude)
Shadow length
0 m
Noon shadow — from latitude & date
| Shadow length | 17.32 m |
| Shadow / height ratio | 1.73x |
| Noon sun altitude | 32.4° |
| Noon shadow length | 15.78 m |
⚠️ Reference values from astronomical sun altitude and azimuth, assuming flat ground. Real shadows vary with terrain slope, nearby buildings and atmospheric refraction; for right-to-light disputes or permits, use a professional sunlight analysis. calcstool.com assumes no liability for these results.
FAQ
How is shadow length calculated?
Shadow length = object height ÷ tan(sun altitude). The lower the sun, the longer the shadow; the shadow is shortest at solar noon when the sun is highest.
How is noon shadow found?
From latitude and date we compute the noon sun altitude (= 90 − latitude + solar declination), then the shadow length at that altitude. Useful for solar access and building setbacks.
Can I use it for solar access?
Yes. The winter solstice (around Dec 22) noon shadow is the longest and is the worst-case for solar access analysis. Set the date to the solstice to check it.