Paper size finder: what size is this?

How the size finder works

The calculator compares your measurements with every size listed on this website and sorts them by the largest deviation on either side. Orientation does not matter: 297 × 210 mm is recognised as A4 just like 210 × 297 mm.

If the deviation is within the ISO 216 tolerance (±1.5 mm up to 150 mm, ±2 mm up to 600 mm, ±3 mm above that), the calculator reports a match. Otherwise it shows the nearest size and the difference.

Typical cases

• A sheet from the US: 216 × 279 mm is recognised as Letter, not A4.
• A pixel size from an image editor: choose pixels as the unit and enter the resolution, for example 2480 × 3508 pixels at 300 dpi.
• An envelope: 114 × 229 mm gives C6/5, 110 × 220 mm gives DL.
• A press sheet: 320 × 450 mm is SRA3.

Frequently asked questions