Outdoor map tool
Building, Wall and Tree Shadow Calculator
This calculator turns a verified obstacle height into a visible outdoor shadow. Place a building, wall or tree on the map, set its dimensions and then move the time control to see how direction and length change.
- Cost
- Free
- Account
- Not required
- Project data
- Browser-local
Loading the global map…
Click once to move the receiving point.
What this tool calculates
- Geometric shadow length from obstacle height and solar altitude
- Shadow bearing opposite the solar azimuth
- A plan-view footprint for buildings and walls
- A softer, opacity-aware approximation for tree crowns
How to use it
- 01
Place the receiving point
Mark the patio, garden or outdoor area whose shade matters.
- 02
Add the obstruction
Choose Building, Wall or Tree and click its location. Add the best height and width you can verify.
- 03
Test critical times
Check morning, midday and afternoon on dates near both solstices before drawing a conclusion.
How to read the result
Hard-edged shadows
Buildings and walls are treated as opaque geometry, so their plan-view shadows have firm boundaries.
Tree shade
Tree opacity changes visual density, not leaf-by-leaf light transmission. Compare leafy and sparse seasons manually.
Limits you should know
- Roof shapes, overhangs and uneven terrain require manual simplification.
- Tree height, crown shape and seasonal foliage are estimates.
- The result is a planning aid, not a substitute for a professional survey or solar-access study.
Questions about this calculator
What is the shadow-length formula?
For level ground, length is obstacle height divided by the tangent of solar altitude. SunCarta caps extreme display lengths near the horizon so the map remains usable.
Can I rotate a building?
Yes. Select the building and adjust Rotation so its plan footprint follows the real structure more closely.
Methodology version 1.1 · Reviewed August 8, 2026