How tall a mirror do you need?

To see yourself from head to toe in a flat mirror, the mirror needs to be at least half your height: 2 ft 10.5 in (87.5 cm) for someone 5 ft 9 in (175 cm). Standing closer or farther away does not change it, but the mirror has to hang at the right height.

Draw yourself to scale

The mirror needs half your height, at any distance: light from your head and your feet reaches your eyes off its top and bottom edges. Outlines are symbols, not to scale.

Why half your height is enough

Light from the top of your head reaches your eyes by bouncing off the mirror halfway between your eyes and the top of your head. Light from your feet bounces off the mirror halfway between your eyes and the floor. Only the part of the mirror between those two points is used, and it is exactly half your height.

Step back and the reflection gets smaller at the same rate as the distance grows, so the half-height rule holds at any distance. That is why stepping back from a short mirror does not show more of you.

Where to hang it

Put the top edge halfway between your eyes and the top of your head, and the bottom edge halfway between your eyes and the floor. Hung lower, the mirror cuts off your head; hung higher, it cuts off your feet.

To see your shoes as well, go by your height in them: every inch of sole or heel adds half an inch to the mirror you need.

When people of different heights share one mirror, it has to cover each of them: the top edge high enough for the tallest, the bottom edge low enough for the shortest. That is why full-length mirrors are usually taller than half of anyone’s height.

Why photos and mirrors disagree with the tape

A mirror shows you at your true height relative to the room behind you. A photo does not: whoever stands closer to the lens looks taller, and a camera held low makes people look taller than one held high. For a fair photo comparison, stand side by side, at the same distance, with the camera at about chest height.

A tape measure against a wall is still the only way to know your height; the guide to measuring at home shows how.

Try the same example

Draw yourself to scale. The names, units and values carry into the editable chart.

For the arithmetic alone, use the height difference calculator. For a different unit, use the height converter.

The next useful step

How the charts work explains the shared scale, source precision and custom inputs.