Print & Typography Units Converter
指导
Print & Typography Units Converter
A live, bi-directional converter for the units designers, print professionals and front-end developers reach for every day: points, picas, pixels, millimetres, centimetres, inches, em and rem. Type into any unit and the rest update instantly using the DPI and font size you choose, so values match the actual medium you are designing for — screen at 96 DPI, draft print at 150, or production print at 300 and beyond.
如何使用
- Type a value into any unit field — pixels, points, picas, mm, cm, inches, em or rem.
- All other units recalculate live based on the current DPI and font size settings.
- Pick a DPI preset (72, 96, 150, 300, 600) or enter a custom DPI for your output medium.
- 调整 Root Font Size for rem conversions and Parent Font Size for em conversions.
- Use the reference tables below the form to scan common print and screen sizes in every unit at the chosen DPI.
特征
- Eight units, bi-directional — px, pt, pc (pica), mm, cm, inch, em and rem all stay in sync as you type.
- Custom DPI with presets — one-click 72, 96, 150, 300 and 600 DPI plus any value from 1 to 2400.
- Configurable font sizes — independent root and parent font sizes so em and rem behave the way they will on your site.
- Common Print Sizes table — quick reference for body and display point sizes converted to every other unit.
- Common Screen Sizes table — px values from 10 to 64 mapped to pt, rem, em and mm at your current DPI.
- Copy on every field — one-click copy of any converted value for pasting into CSS, Figma, Illustrator or InDesign.
- 纯客户端运行 — no server round-trip, no telemetry, instant feedback as you type.
常问问题
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Why is 1 inch defined as 72 points?
The 72-points-per-inch standard comes from PostScript and modern digital typography. It is convenient because 72 has many divisors (2, 3, 4, 6, 8, 9, 12, 18, 24, 36), which makes typographic math easy. Traditional printers used a slightly different value (about 72.27 pt/in for the Anglo-American point), but PostScript rounded it to exactly 72 and that convention is now universal in design software, CSS, and PDF.
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DPI 和 PPI 有什么区别？
DPI (dots per inch) and PPI (pixels per inch) measure pixel/dot density, but they apply to different mediums. PPI refers to screen pixel density (a 96-PPI monitor has 96 pixels in every horizontal inch). DPI refers to ink dots a printer places per inch. In CSS the two are conflated and a CSS pixel is defined as 1/96 inch, so 96 DPI is the standard reference when converting between print and screen units.
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What is the difference between em and rem?
Both em and rem are relative typographic units. 1em equals the computed font size of the element where it is used (so it cascades from the parent), while 1rem always equals the font size of the root element. rem gives predictable, document-wide scaling, while em adapts locally and can compound when nested.
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What is a pica and where is it still used?
A pica is a print-industry unit equal to 12 points, or 1/6 of an inch (about 4.233 mm). Picas are still used in newspaper and book typesetting to describe column widths, line lengths, and gutters because they map cleanly to point-based body text (a 12-point line in a 24-pica column is intuitive for a typographer to reason about).
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Why does the pixel size depend on DPI?
A pixel is a device-relative unit: it represents one addressable dot on a screen or one print dot in a rasterised output. The physical size of that dot depends on how densely the dots are packed (the DPI/PPI). At 96 DPI, 96 pixels span one inch; at 300 DPI, 300 pixels span the same inch, so each pixel is physically smaller. That is why the same image looks sharper in print at higher DPI.
