convertimate Paper sizes (A4, A3, Letter)

A series to B series

Type a value in A to get it in B instantly.

≈B4B

That's about the same as an A3 sheet. With ISO proportions that is a sheet of about 297.3 × 420.4 mm (11.7 × 16.55 in).

What it means

How big is that sheet?

ISO 216 sizes are rounded to whole millimeters on real sheets. US sizes are compared by area; their proportions differ from √2.

The math

How to convert A to B

Area of A n = 2^−n m²; B n = 2^(½−n) m², C n = 2^(¼−n) m². Sides are in the ratio 1 : √2.

Example: A3 A = ≈B4 B.

Every unit

That sheet in every system

Tables

A to B conversion table

A to B conversion table
AB
A0 A≈B1 B
A1 A≈B2 B
A2 A≈B3 B
A3 A≈B4 B
A4 A≈B5 B
A5 A≈B6 B
A6 A≈B7 B
A7 A≈B8 B
A8 A≈B9 B
A9 A≈B10 B
A10 A≈B11 B
B to A conversion table
B to A conversion table
BA
B1 B≈A1 A
B2 B≈A2 A
B3 B≈A3 A
B4 B≈A4 A
B5 B≈A5 A
B6 B≈A6 A
B7 B≈A7 A
B8 B≈A8 A
B9 B≈A9 A
B10 B≈A10 A
B11 B≈A11 A

Quick answers

Quick answers

How many B is A1 A?
A1 A is ≈B2 B.
How many B is A10 A?
A10 A is ≈B11 B.
How many B is A3 A?
A3 A is ≈B4 B.

The units

About these units

A series (A)

ISO A sizes: A0 is 1 m², A4 a sixteenth.

B series (B)

ISO B sizes, between the A sizes; posters and passports.

Learn more about sheet units

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