Door Measuring Guide

Development guide content — written for structure and internal-linking testing. Review before launch.

Before you measure

Always measure the door leaf itself, not the frame opening, if you are replacing a door into an existing frame.

Measuring an existing door

1. Measure the height of the existing door leaf at its tallest point.
2. Measure the width at its widest point.
3. Measure the thickness — internal doors are commonly 35mm, fire doors 44mm.

Measuring a new opening

Measure the structural opening height and width, then deduct the frame thickness on each side.

Standard UK internal door sizes

Common sizes include 1981 x 610mm, 1981 x 686mm, 1981 x 762mm and 1981 x 838mm.

Still unsure?

Call 01924 457457 or use our contact form. If no standard size fits, see Custom Doors.