Location
London, United KingdomDate & time
Object
Shadow length
2.56 m
Drag to rotate
Shadow Length Calculator
The SunCast shadow length calculator shows the length and direction of a vertical object’s shadow on level ground. Set a location, date, local time and height, then explore the animated 3D scene. It uses solar geometry, not a weather forecast or a survey of surrounding buildings.
- Find a place. All times follow that location’s time zone.
- Choose a date and object height in metres or feet.
- Move the time slider or play the day to see the shadow change.
How is shadow length calculated?
Shadow length = height ÷ tan(sun elevation). A 2 m object casts a 2 m shadow when the sun is 45° above the horizon. Lower sun angles produce longer shadows.
The shadow points in the opposite direction to the sun: add 180° to the sun’s azimuth. Bearings are measured clockwise from true north.
The dimension measures the ground distance from the object’s centre to the projection of its top centre. The shaded footprint also includes the object’s width.
Shadow calculator questions
Can I use this for a tree or building?
Use the height to estimate the shadow distance of a vertical object. The scene shows a simple pillar or block; it does not model branches, roofs, nearby buildings or terrain. The measurement runs from the base centre to the ground projection of the top centre.
Why is the shadow so long near sunrise and sunset?
The sun’s elevation approaches zero, so height divided by its tangent grows very large. Shadows extend beyond the sun-path ring. Zoom out to see more of a long shadow; the readout gives the full distance. At or below the horizon, there is no direct sunlight shadow in this model.
Which time zone does the calculator use?
The date and time are local to the selected location, including daylight-saving time. Changing location keeps the selected clock time. Now selects the current date and time there.
Does the scene account for clouds or sloping ground?
No. It assumes a vertical object, horizontal ground and an unobstructed sun. Clouds can soften or remove a visible shadow, and slopes or surrounding objects can change where it falls.
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