A3 vs ANSI B
A3 is 17.6 mm wider and 11.8 mm shorter than ANSI B. They are close but not interchangeable: a layout built for one clips or leaves a border on the other.
Compare a Different Pair
A3 and ANSI B, Side by Side
| A3 | ANSI B | Difference | |
|---|---|---|---|
| Millimetres | 297 × 420 | 279.4 × 431.8 | 17.6 × 11.8 mm |
| Inches | 11.69 × 16.54 | 11 × 17 | 0.69 × 0.46 in |
| Centimetres | 29.7 × 42.0 | 27.9 × 43.2 | |
| Area | 0.125 m², 124,740 mm² | 0.121 m², 120,645 mm² | 1.03× |
| Aspect ratio | 1 : 1.414 (√2) | 1 : 1.545 | different |
What Is Lost Printing One on the Other
At 100% scale, both centred, nothing resized. A positive figure on the wider or taller side is cropped; on the other it is a blank margin.
| Axis | Gap | A3 onto ANSI B | ANSI B onto A3 |
|---|---|---|---|
| Width | 8.8 mm (0.35 in) each side | A3 loses it | blank band |
| Height | 5.9 mm (0.23 in) each end | blank band | ANSI B loses it |
Scale-to-Fit Percentages
The figure to type into a printer or PDF dialog to scale one to fit inside the other:
| ANSI B to fit A3 | 97% | leaves a thin border on one pair of edges |
|---|---|---|
| A3 to fit ANSI B | 94% | leaves a thin border on one pair of edges |
Beyond the Measurements
Envelopes: A3 fits C3; ANSI B has none.
Frequently Asked Questions
Is A3 bigger than ANSI B?
A3 is bigger. It is 297 × 420 mm against 279.4 × 431.8 mm for ANSI B, about 1.03 times the area.
What is the difference between A3 and ANSI B?
A3 is 17.6 mm wider and 11.8 mm shorter than ANSI B. They are close but not interchangeable: a layout built for one clips or leaves a border on the other.
Can you print ANSI B on A3?
Not at full size without a change. Shrink ANSI B to 97% to fit A3, which leaves a thin border, or print at 100% and lose 8.8 mm off each side and 5.9 mm top and bottom.
✓ Dimensions per the standards on the A3 and ANSI B pages. Differences and scale factors computed. Reviewed . Editorial Process →