Figure Height at a Distance Calculator
How tall does a 1.8 m person look at 12 metres through a 35 mm lens? Exactly this tall, and their feet go exactly here.
How big does a figure look at a distance?
Apparent height is simple: height in the picture = focal length × real height ⁄ distance, where the focal length is expressed in the picture's own pixels (or inches). Double the distance and the figure is half as tall; use a lens twice as long and the figure is twice as tall. This calculator does that arithmetic for any subject, distance, lens and frame size, and adds the part illustrators actually need: where the feet and head sit relative to the horizon.
The eye-level trick
With a level camera, anything at the camera's height appears exactly on the horizon line, no matter how far away it is. For a viewer standing at 1.6 m, every standing adult's eyes are on or just above the horizon, whether the person is three metres away or thirty. What changes is how far the feet fall below the horizon (closer means lower) and how tall the whole figure is. Draw the eye line first, then measure the height at the figure's distance, and the figure will always sit correctly on the ground.
The same rule works for any object once you know its height relative to eye level: door tops (2.1 m) are above the horizon, car roofs (1.5 m) are just below it, a table top (0.75 m) is well below.
Using the result
Take the apparent height and feet position and mark them on your drawing at the same frame proportions. Or open the 2-point grid at the same lens: the one-metre reference cube and one-metre floor squares show the same scale directly, and the horizon calculator handles the case where the camera is tilted.
Questions
How do I scale a person in perspective?
Everything at the height of the viewer's eye sits on the horizon. If your eye level is 1.6 m and a person is 1.8 m tall, their eyes are just above the horizon at every distance; their feet drop further below it the closer they are. Apparent height is proportional to 1 ⁄ distance: twice as far, half as tall.
Why do my figures look too big or too small?
Usually the eye level is inconsistent. Decide the horizon height once, put every figure's eye line on it (for standing adults on level ground), and let the feet fall where the distance puts them. This calculator gives the exact numbers.
Does the lens change how big a person looks?
Yes. At the same distance a 24 mm lens shows the figure at half the size a 50 mm does, because the frame covers twice the width. The relative sizes of two figures at different distances do not depend on the lens at all.