Font Size Converter
Convert a font size between points, pixels, em, rem, percent, millimeters, inches and picas. The converter follows the CSS definitions — 96 pixels and 72 points to the inch — and lets you set the root and parent font sizes that em, rem and % depend on.
Browsers start at 16 px. Change these if your stylesheet sets another size on the html element or on the parent.
12 pt in every unit
| Unit | Size | CSS | Copy |
|---|---|---|---|
| Points (pt) | 12 | 12pt | |
| Pixels (px) | 16 | 16px | |
| em | 1 | 1em | |
| rem | 1 | 1rem | |
| Percent (%) | 100 | 100% | |
| Millimeters (mm) | 4.2333 | 4.2333mm | |
| Centimeters (cm) | 0.4233 | 0.4233cm | |
| Inches (in) | 0.1667 | 0.1667in | |
| Picas (pc) | 1 | 1pc |
Working
- 12 pt × 96 ÷ 72 = 16 px
- 16 px ÷ 16 px = 1 em
- 16 px ÷ 16 px = 1 rem
- 16 px × 25.4 ÷ 96 = 4.2333 mm
Word on Windows and Google Docs size type in points and treat an inch as 96 pixels, so at 100% zoom 12-point text is drawn at the same size as 16px text in a browser.
Common point sizes
em, rem and % use the root and parent sizes above.
| Points | Pixels | em | rem | % | mm |
|---|---|---|---|---|---|
| 6 | 8 | 0.5 | 0.5 | 50 | 2.12 |
| 7 | 9.33 | 0.583 | 0.583 | 58.3 | 2.47 |
| 8 | 10.67 | 0.667 | 0.667 | 66.7 | 2.82 |
| 9 | 12 | 0.75 | 0.75 | 75 | 3.18 |
| 10 | 13.33 | 0.833 | 0.833 | 83.3 | 3.53 |
| 10.5 | 14 | 0.875 | 0.875 | 87.5 | 3.7 |
| 11 | 14.67 | 0.917 | 0.917 | 91.7 | 3.88 |
| 12 | 16 | 1 | 1 | 100 | 4.23 |
| 14 | 18.67 | 1.167 | 1.167 | 116.7 | 4.94 |
| 16 | 21.33 | 1.333 | 1.333 | 133.3 | 5.64 |
| 18 | 24 | 1.5 | 1.5 | 150 | 6.35 |
| 20 | 26.67 | 1.667 | 1.667 | 166.7 | 7.06 |
| 22 | 29.33 | 1.833 | 1.833 | 183.3 | 7.76 |
| 24 | 32 | 2 | 2 | 200 | 8.47 |
| 28 | 37.33 | 2.333 | 2.333 | 233.3 | 9.88 |
| 32 | 42.67 | 2.667 | 2.667 | 266.7 | 11.29 |
| 36 | 48 | 3 | 3 | 300 | 12.7 |
| 48 | 64 | 4 | 4 | 400 | 16.93 |
| 72 | 96 | 6 | 6 | 600 | 25.4 |
How to Use the Font Size Converter
- 1. Enter a size and its unit. Type 12 and choose points, or 24 and choose pixels — any of the nine units can be the starting point.
- 2. Set the reference sizes if you need to. rem is measured against the root (
html) font size, and em and % against the parent element's. Both start at 16 px, the browser default. - 3. Read the size in every unit. Each row gives the value and the CSS to paste, with a copy button, and the working shows each conversion through pixels.
- 4. Check the table of common sizes. The point sizes of a word-processor menu, from 6 to 72, are listed with their pixel, em, rem, percent and millimeter equivalents.
The Conversion Rules
CSS fixes the physical units against each other: an inch is 96 pixels, 72 points, 6 picas or 25.4 millimeters. A point is therefore exactly 4/3 of a pixel. The relative units need one more number — the font size they are measured against.
| Unit | To pixels | From pixels |
|---|---|---|
| Points (pt) | px = pt × 96 ÷ 72 | pt = px × 72 ÷ 96 |
| Picas (pc) | px = pc × 16 | pc = px ÷ 16 |
| Millimeters (mm) | px = mm × 96 ÷ 25.4 | mm = px × 25.4 ÷ 96 |
| Inches (in) | px = in × 96 | in = px ÷ 96 |
| em | px = em × parent size | em = px ÷ parent size |
| rem | px = rem × root size | rem = px ÷ root size |
| Percent (%) | px = % × parent size ÷ 100 | % = px ÷ parent size × 100 |
Root and parent sizes are in pixels; both are 16 px unless a stylesheet changes them.
With the defaults, 12 pt is 12 × 96 ÷ 72 = 16 px. Then 16 ÷ 16 gives 1 em, 1 rem and 100%, and 16 × 25.4 ÷ 96 gives 4.2333 mm. Set the parent size to 20 px and the same 16 px becomes 0.8 em and 80% — but it stays 1 rem, because rem ignores the parent.
Why 12 pt Equals 16 px
A point is 1/72 of an inch and a CSS pixel is 1/96 of an inch, so 12 points is 12/72 = 1/6 inch, which is 96 ÷ 6 = 16 pixels. Word on Windows and Google Docs also treat an inch as 96 pixels on screen, so at 100% zoom 12-point text there looks the same size as 16px text in a browser — and 16 px is the size browsers use for text that no stylesheet has sized.
A CSS pixel is not necessarily one dot of your screen. On a high-density display one CSS pixel covers several device pixels, and the browser scales every unit together, so the ratios above always hold. LaTeX is the one common exception to the 72-point inch: its pt is the printer's point, 72.27 to the inch, so a LaTeX 12pt is about 0.4% smaller than 12 pt in Word or CSS. TeX's bp ("big point") is the 72-to-the-inch point this converter uses.
Font Sizes for Academic Papers
Style guides set type sizes in points, so a paper's font never needs converting — but it helps to know what each guide actually asks for:
- APA 7 names font-and-size pairs rather than one size: 11-point Calibri, 11-point Arial, 10-point Lucida Sans Unicode, 12-point Times New Roman, 11-point Georgia, or 10-point Computer Modern.
- MLA 9 asks for an easily readable typeface whose italic contrasts with the regular style, at a size between 11 and 13 points unless your instructor says otherwise.
- Turabian (Chicago style for students): the official tip sheet suggests 12-point Times New Roman or Calibri, or 11-point Arial.
Fonts look different at the same point size — Arial reads larger than Times New Roman — which is why APA pairs each font with its own size. For margins, spacing, headers and the rest of the page, see How to Format an Academic Paper in APA, MLA, and Chicago.
Frequently Asked Questions
- How many pixels is 12 pt?
- 16 pixels. CSS defines an inch as 96 pixels and as 72 points, so one point is 4/3 of a pixel and 12 × 4/3 = 16. The same rule makes 10 pt 13.33 px, 11 pt 14.67 px and 14 pt 18.67 px.
- How do I convert px to rem?
- Divide by the root font size. At the default 16 px, 24 px is 24 ÷ 16 = 1.5rem and 14 px is 0.875rem. If your stylesheet gives the
htmlelement another size, enter it as the root size and the converter uses that instead. - What is the difference between em and rem?
- Both are relative to a font size, but to different ones. rem always refers to the root (
html) element, so 1.5rem is the same size everywhere on the page. em refers to the parent element, so 1.5em inside a box whose text is already 1.5em comes out at 2.25 times the root size — em compounds, rem does not. - Is 1em always 16px?
- Only by default. 1em equals the parent element's font size and 1rem the root's, and browsers start both at 16 px. A reader who raises the default text size in their browser settings changes that starting point, which is why text sized in rem or em follows their choice and text sized in px does not.
- How big is 12 pt in millimeters?
- 12 points is 1/6 inch, or about 4.23 mm. That is the size of the font's em box, the design space each letter is drawn in, not the height of a capital letter, which in common text fonts is roughly two-thirds of it.
- Why does the same point size look bigger in some fonts?
- Point size sets the em box, not the visible letters. Fonts draw their letters at different proportions inside that box — Arial has taller lowercase letters than Times New Roman — so 12-point Arial looks larger. That is why APA 7 pairs 11-point Arial with 12-point Times New Roman instead of giving one size for every font.