B5 Paper Size — 176 × 250 mm and Inches

B5 paper size is 176 × 250 millimeters. In inches, rounded to two decimals, that is 6.93 × 9.84. The millimeters are the ISO 216 B-series size. The inches are a conversion, not a second standard.

The B series sits between the A sizes. Each B sheet is the geometric mean of the A sheet with the same number and the A sheet one step larger. You do not need that formula to spec a job. You need the millimeters, and you need to know that B5 is a notebook and booklet size, not a replacement for A4. The series is listed in Markus Kuhn’s ISO 216 summary (International standard paper sizes).

B5 dimensions

Unit	Width	Height
Millimeters	176	250
Centimeters	17.6	25.0
Inches (rounded)	6.93	9.84

Portrait is 176 mm wide. Landscape is 250 mm wide. Japanese notebooks and many paperbacks use portrait B5. A landscape B5 file is the same stock turned. Say which one, because a binder drilled on the long edge will not match a file drilled on the short edge.

B4 and B6

B4 paper size and B6 size are the neighbors. B4 is twice B5. B6 is half of B5. The cut is parallel to the short side, same as the A series.

Size	Millimeters	Inches (rounded)	How it relates to B5
B4	250 × 353	9.84 × 13.90	Two B5 sheets
B5	176 × 250	6.93 × 9.84	The size on this page
B6	125 × 176	4.92 × 6.93	Half of B5

B4 is a folder, a chart, or a newspaper-like magazine page in some countries. It is larger than A4 and smaller than A3. It is not tabloid.

B6 is a pocket book, a small manual, or a notebook that fits a coat. It is close to A6 in spirit and different in numbers. A6 is 105 × 148 mm. B6 is 125 × 176 mm. Do not substitute them in a print run.

B5 and A5

A5 is 148 × 210 mm (5.83 × 8.27 in). B5 is 176 × 250 mm. B5 is larger in both directions, by 28 mm of width and 40 mm of height. That is a different book. A text block designed for A5 will look lost on B5, and a B5 cover will not fit an A5 case.

	Millimeters	Inches (rounded)
A5	148 × 210	5.83 × 8.27
B5	176 × 250	6.93 × 9.84
A4	210 × 297	8.27 × 11.69

People pick B5 when A5 feels small and A4 feels like a document. Textbooks, journals, and planners use it for that reason. Office letters should stay on A4 or US Letter. Those sizes are in A4 Paper Size and US Letter Size.

There is also a B5 envelope, 176 × 250 mm, which holds a C5 envelope. That is an envelope used as an outer sleeve, not the notebook sheet. If the job is mail, start from Envelope Sizes so the insert and the sleeve stay distinct.

ISO B5 is not JIS B5

Japan uses a different B series, JIS P 0138. JIS B5 is 182 × 257 mm. ISO B5 is 176 × 250 mm. The JIS sheet is 6 mm wider and 7 mm taller. Notebooks sold as “B5” in Japan are usually the JIS size. A European printer who hears B5 will cut ISO.

	Millimeters	Inches (rounded)
ISO B5	176 × 250	6.93 × 9.84
JIS B5	182 × 257	7.17 × 10.12
JIS B4	257 × 364	10.12 × 14.33
JIS B6	128 × 182	5.04 × 7.17

Write “ISO B5” or “JIS B5” on the ticket. “B5” alone is how a run gets trimmed to the wrong rectangle. This page’s main figures are ISO. Use the JIS row only when the brief is a Japanese notebook or a Japanese official form.

Setting up a B5 file

Set the page to 176 × 250 mm. Margins live inside that. A book often needs a larger inside margin for the gutter. Add the gutter in the layout, not by changing the page size to 180 mm or some other round number. The printer’s imposition wants the ISO trim.

Bleed, if the cover runs off the edge, sits outside 176 × 250. Confirm the amount. Three millimeters is a frequent digital-print request. It is not part of B5.

Paper weight is a separate choice. B5 does not imply a thickness. A planner and a poster can share the trim and use different stock. Write the weight in the spec next to the size.

FAQ

What is B5 size in inches?

6.93 × 9.84 inches, rounded from 176 × 250 mm. Spec the millimeters.

Is B5 the same as A5?

No. A5 is 148 × 210 mm. B5 is 176 × 250 mm. B5 is larger on both sides.

What is B6 paper size?

125 × 176 mm (4.92 × 6.93 in). It is half of B5.

What is B4 paper size?

250 × 353 mm (9.84 × 13.90 in). It is twice B5. It is not A3 and it is not US tabloid.

What to open next

Lock 176 × 250 mm as the trim, then set the gutter. If the piece is a letter rather than a book, switch to A4 before you choose a type size. Every other series is on the Paper Sizes chart.