A-series reference
A3 paper size (297 × 420 mm → 11.69 × 16.54 in)
A3 has nominal trimmed dimensions of 297 × 420 mm, approximately 11.69 × 16.54 inches.
Maintained by mmtoinches.im · Updated
NIST describes the standard inch as exactly equivalent to 25.4 mm
. NIST length definition. ISO 216 — A and B series paper sizes. Method and limitations.
A3 is a versatile size for posters, diagrams, and folded brochures. Use the conversions below to set up A3 files in inches, see how it differs from Tabloid 11×17, and apply bleed plus resolution guidelines for print-ready exports.
Dimensions
- Millimeters: 297 mm × 420 mm
- Inches: 11.69 in × 16.54 in
- Area: about 0.1247 m² (193.0 in²), twice A4
- Ratio: 1:sqrt(2), doubles or halves cleanly when combined with other A sizes
Print setup tips
For fold-out brochures, leave 2–3 mm at the fold for trimming. Printing on a Tabloid (11×17) device? Choose Scale to fit and center align to keep the full design.
Common uses
Posters and notices
Great size for store signage, event posters, and quick visual displays that stay portable.
Design drafts
Handy for architectural diagrams, product sketches, and review prints with more room than A4.
A3 vs Tabloid
Tabloid is a bit wider and taller; center the artwork and let the printer scale to fit to avoid stretch.
Print-resolution, bleed and margin examples are starting points, not ISO paper-size requirements. Follow the printer or publisher’s specifications; vector PDF content does not have a single image DPI.
Frequently Asked Questions
A3 is 297 × 420 millimeters, approximately 11.69 × 16.54 inches. It keeps the 1:sqrt(2) aspect ratio and has double the area of A4.
Tabloid is 279.4 × 431.8 mm (11 × 17 in), slightly wider and taller than A3. When printing A3 art on a Tabloid device, use Scale to fit and center to avoid clipping.
Add at least 3 mm bleed on all sides and keep a 5–8 mm safe zone for text. Export at 300 dpi or higher in CMYK for crisp digital or inkjet output.
Sources and calculation notes
A3 has nominal trimmed dimensions of 297 × 420 mm, approximately 11.69 × 16.54 inches.
Method: Divide millimeters by 25.4 to obtain inches. The factor is exact; displayed decimal values are rounded. Fractional inches are rounded to the selected denominator.
Scope: The mm dimensions are nominal ISO trimmed sizes; inch values are rounded. Add bleed or printer margins separately.
Content maintained by mmtoinches.im. Updated and reference notes reviewed . How we calculate and present measurements. Sources support the stated definitions; examples and calculators are not certification of a product or compliance with a standard.