A4 paper measures 210mm x 297mm. The table below displays the dimensions of A4 paper in millimetres in portrait.
Paper Size Type | Paper Width | Paper Height |
A4 Dimensions | 210 mm | 297 mm |
Letter Dimensions | 216 mm | 280 mm |
Letter size: Canada and the United States of America.
A4 size in mm: United Kingdom, Australia, Germany, Singapore, India, United Arab Emirates, Philippines, New Zealand and nearly ever other country in the world.

What are Millimetres?
Millimetres are also known as mm and are part of the metric system of measurement system.
Millimetres are one tenth of a centimetre and one thousandth of a metre.
Millimetres are most used for measuring small distances.