Paper Size Reference
Paper Size Reference
ISO A / B / C series · US sizes · mm to inches
| Size | W × H (mm) | W × H (inch) | Typical use |
|---|
How to Use
📖 Tool Introduction
Paper Size Reference is an offline lookup panel built for designers, print-shop staff, students and office clerks who run into sheet sizes every single day. Printing a resume means picking A4; designing a poster means weighing A2 against A1; mailing a handwritten letter means choosing the right envelope; and a business trip to North America suddenly confronts you with Letter and Legal, dimensions that have nothing to do with the metric system. This tool lays out the full ISO 216 A, B and C series from size 0 all the way down to size 10, and adds the five common North American formats you meet in offices: Letter, Legal, Tabloid, Executive and Junior Legal. Every row shows the nominal millimetre size next to the converted inch size, and adds a note on what that format is typically used for in the real world. The side tabs let you flip between A, B, C envelopes and US sizes in one click, while the A4 row stays highlighted by default as a reminder that this is the most widely used office sheet on the planet. The inch figures are recalculated live from one inch equals twenty-five point four millimetres, so there is no rounding drift introduced by a hand-typed lookup table. You can also copy the whole current series as tab-separated text, or export it as a CSV that opens straight in Excel, which is handy when you need to double-check margins in a layout tool or annotate finished sizes on a print quote. The tool makes no network request, loads instantly, and on a phone the side tabs collapse into a horizontal row while the table scrolls sideways, so every column stays readable on a small screen. It is meant to be the quickest possible answer to questions like what envelope fits an A5 letter, or how big a Tabloid sheet really is in centimetres, without opening a PDF standard document just to grab one number.
✨ Key Features
- Complete ISO coverage: A0 through A10, B0 through B10 and C0 through C10 all listed
- US formats included: Letter, Legal, Tabloid, Executive and Junior Legal at a glance
- Dual units: nominal millimetres beside live-converted inches at 1 in = 25.4 mm
- Usage notes: each row says what the size is typically used for, so beginners match instantly
- Copy and CSV export of the current series for design work and print quotes
- Fully offline and self-contained, instant load, no network calls
📝 How to Use
- Click a side tab to choose the series you want: A, B, C envelopes or US sizes
- The table on the right switches instantly, with the A4 row highlighted by default
- Each row shows size name, millimetres, inches and typical use, left to right
- Click any row to highlight it for quick comparison
- Use Copy table or Export CSV to take the current series with you
⚠️ Notes
- Nominal sizes: millimetre values follow ISO 216 nominal dimensions; real trimming may vary by one or two millimetres
- Aspect ratio: every ISO sheet keeps a √2 ratio, so folding an A sheet once gives the next smaller A size
- Envelope fit: the C series is for envelopes; C4 holds A4 unfolded, C5 holds A5 letters
- US mismatch: Letter and Legal are not metric-proportional, so confirm the region before cross-border printing
- Offline safe: switching series, copying and exporting all work without a connection