JIS B6 vs A8 Envelope (US)

Q: Which is bigger, JIS B6 or A8 Envelope (US)?

A8 Envelope (US) — 139.7 × 206.375 mm against 128 × 182 mm, which is 23.8% more area.

	JIS B6	A8 Envelope (US)
Millimetres	128 × 182	139.7 × 206.375
Inches	5.04 × 7.17	5.5 × 8.13
Centimetres	12.8 × 18.2	14 × 20.6
Aspect ratio	1:1.42	1:1.48
Area	233 cm²	288.3 cm²

Which is bigger

A8 Envelope (US), by 23.8% in area. A8 Envelope (US) is 11.7 mm wider than JIS B6. A8 Envelope (US) is 24.4 mm taller.

Printing one on the other

A JIS B6 page fits inside A8 Envelope (US) whole — print it at 100% and you get a 5.8 mm border down each side and 12.2 mm top and bottom.

You want	Set the print scale to	Leaves
JIS B6 artwork on A8 Envelope (US) paper	109.1%	0 × 7.7 mm margin
A8 Envelope (US) artwork on JIS B6 paper	88.2%	4.8 × 0 mm margin

These are the numbers for the "custom scale" box in a print dialog. "Fit to page" computes the same thing, but knowing the figure tells you in advance whether the result will look deliberate or accidental.

Why the shapes matter

The proportions differ: JIS B6 is 1:1.42 and A8 Envelope (US) is 1:1.48. That difference is why a layout moved between them never quite lines up — scale it to fit one edge and the other is left with 7.7 mm of unwanted margin.

Frequently asked questions

What is the difference between JIS B6 and A8 Envelope (US)?

JIS B6 is 128 × 182 mm and A8 Envelope (US) is 139.7 × 206.375 mm. A8 Envelope (US) is the larger of the two by 23.8% in area.

Can I print JIS B6 on A8 Envelope (US)?

Yes, at 100% — JIS B6 is smaller on both edges, so it lands inside A8 Envelope (US) with a border all round.

Which is bigger, JIS B6 or A8 Envelope (US)?

A8 Envelope (US) — 139.7 × 206.375 mm against 128 × 182 mm, which is 23.8% more area.

Related comparisons

JIS B6 in full · A8 Envelope (US) in full · All size comparisons · All paper sizes