Print & Layout
Paper Size Conversion (mm to inches)
Use nominal paper dimensions for A-series and B-series formats, then convert each side independently. ISO B5 and JIS B5 are different sizes.
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.
Convert A-series paper sizes from millimeters to inches and compare them with US Letter, Legal, and Tabloid. Understand rounding and margin differences before you print or design.
Conversion formulas
inches = mm ÷ 25.4
mm = inches × 25.4
Displayed values are rounded to two decimals for readability; the conversion factor is exact, while calculated results use floating-point arithmetic. Retain the nominal mm dimensions for layout planning.
Need custom sizes?
Use the mm to inches converter to handle custom dimensions with full decimal precision, then apply rounding as needed for printing.
DPI to pixels calculator
Convert paper dimensions to pixel sizes using common DPI presets. Supports A-series and US Letter/Legal/Tabloid with portrait/landscape orientation.
A4 Paper Size
Select a paper size and DPI to get pixel dimensions. Toggle orientation to match your layout.
Display controls
Switch unit and orientation. Copy dimensions quickly for your design specs.
A-series sizes
A0–A10 in millimeters and inches.
| Size | Dimensions (mm) | Copy |
|---|---|---|
| A0 | 841 × 1189 | |
| A1 | 594 × 841 | |
| A2 | 420 × 594 | |
| A3 | 297 × 420 | |
| A4 | 210 × 297 | |
| A5 | 148 × 210 | |
| A6 | 105 × 148 | |
| A7 | 74 × 105 | |
| A8 | 52 × 74 | |
| A9 | 37 × 52 | |
| A10 | 26 × 37 |
US paper sizes
Letter, Legal, Tabloid in inches and millimeters.
| Size | Dimensions (mm) | Copy |
|---|---|---|
| Letter | 215.9 × 279.4 | |
| Legal | 215.9 × 355.6 | |
| Tabloid | 279.4 × 431.8 |
US ANSI sizes
ANSI A–E engineering formats.
| Size | Dimensions (mm) | Copy |
|---|---|---|
| ANSI A | 215.9 × 279.4 | |
| ANSI B | 279.4 × 431.8 | |
| ANSI C | 431.8 × 558.8 | |
| ANSI D | 558.8 × 863.6 | |
| ANSI E | 863.6 × 1117.6 |
Set orientation to match your drawing layout. For portrait, width × height. For landscape, height × width.
B-series sizes
B0–B10 in millimeters and inches.
| Size | Dimensions (mm) | Copy |
|---|---|---|
| B0 | 1000 × 1414 | |
| B1 | 707 × 1000 | |
| B2 | 500 × 707 | |
| B3 | 353 × 500 | |
| B4 | 250 × 353 | |
| B5 | 176 × 250 | |
| B6 | 125 × 176 | |
| B7 | 88 × 125 | |
| B8 | 62 × 88 | |
| B9 | 44 × 62 | |
| B10 | 31 × 44 |
C-series sizes (envelopes)
Designed to fit A-series paper.
| Size | Dimensions (mm) | Copy |
|---|---|---|
| C0 | 917 × 1297 | |
| C1 | 648 × 917 | |
| C2 | 458 × 648 | |
| C3 | 324 × 458 | |
| C4 | 229 × 324 | |
| C5 | 162 × 229 | |
| C6 | 114 × 162 | |
| C7 | 81 × 114 | |
| C8 | 57 × 81 | |
| C9 | 40 × 57 | |
| C10 | 28 × 40 |
Aspect ratio notes
- ISO 216 A-series uses a fixed √2 ratio (~1:1.414). Halving or doubling preserves shape.
- US sizes vary: Letter ~1.294, Legal ~1.647, Tabloid ~1.545. Not a single standard ratio.
- B- and C-series follow ISO logic; C envelopes are sized to hold A sheets with room to spare.
- For pixel dimensions, use DPI presets or see the full chart on mm-to-inches chart.
Poster & Photo sizes
Common photo and poster formats.
Photo sizes
| Size | Dimensions (mm) | Copy |
|---|---|---|
| Photo 4×6 | 101.6 × 152.4 | |
| Photo 5×7 | 127 × 177.8 | |
| Photo 8×10 | 203.2 × 254 | |
| Photo 11×14 | 279.4 × 355.6 |
Poster sizes
| Size | Dimensions (mm) | Copy |
|---|---|---|
| Poster 12×18 | 304.8 × 457.2 | |
| Poster 18×24 | 457.2 × 609.6 | |
| Poster 24×36 | 609.6 × 914.4 | |
| Poster 27×40 | 685.8 × 1016 |
Envelope pairing (C-series ↔ A-series)
Comparison tips
A4 vs Letter
A4 is slightly narrower (210 mm vs 216 mm) and taller (297 mm vs 279 mm). Expect small margin differences when printing across regions.
A3 vs Tabloid
A3 is narrower and shorter than Tabloid. Scaling to fit may leave extra margin or slight crop depending on printer settings.
Rounding
Values are shown to two decimals for readability. Calculations are exact using 1 in = 25.4 mm; printers may still add margin offsets.
Frequently Asked Questions
No. A4 is 210 × 297 mm (8.27 × 11.69 in) while Letter is 8.5 × 11 in (215.9 × 279.4 mm). A4 is narrower and taller, so margins and layout shift slightly when printing.
Conversions use the exact factor 1 inch = 25.4 mm. Dimensions are displayed to two decimals for clarity; additional decimals are available if needed for design work.
Check printer default margins and choose “scale to fit” carefully. Provide a 3–5 mm safe area around content that must not be trimmed when printing across A-series and US formats.
Use pixels = inches × DPI. For A4 (8.27 × 11.69 in) at 300 DPI, that is ≈ 2481 × 3507 px. For Letter (8.5 × 11 in) at 300 DPI, it is 2550 × 3300 px. Orientation matters: swap width and height for landscape. Try the on-page DPI → pixels calculator for quick presets (150 / 300 / 600 DPI).
Typical bleed is 3 mm (~0.12 in) on each edge. Keep critical content within a 3–5 mm safe area from all edges to avoid trimming issues. Many consumer printers cannot print edge-to-edge; check device margins and enable “borderless” only if supported.
Pick the closest match (A4 ↔ Letter, A3 ↔ Tabloid), set “scale to fit” carefully, and anticipate small margin shifts. Avoid hard-edge designs near the trim; add bleed and keep text inside the safe area for consistent results across regions.
Convert sizes before you print
Use the mm to inches converter for custom dimensions, then apply the A-series and US references to keep layouts consistent across regions.
Sources and calculation notes
Use nominal paper dimensions for A-series and B-series formats, then convert each side independently. ISO B5 and JIS B5 are different sizes.
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: ISO 216 defines trimmed A and B series formats. US and JIS formats use other conventions; bleed, printer margins and pixel dimensions are separate settings.
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.