What is the formula to convert points to rem?

First convert points to pixels: px = pt × (96 ÷ 72). Then convert pixels to rem: rem = px ÷ rootFontSizePx. Combined: rem = pt × (96 ÷ 72) ÷ rootFontSizePx. With the default 16px root, 12pt = 16px = 1rem.

Why is 96 used in the formula?

The CSS reference pixel is defined at 96 DPI (dots per inch). A typographic point is 1/72 of an inch. So 1 point = 96/72 pixels ≈ 1.3333px at the standard CSS screen resolution.

What root font size should I use?

Use 16px for the browser default. Some developers set html { font-size: 62.5%; } to get a 10px root (making 1rem = 10px for easier mental math). Use 18px or 20px for larger-base design systems.

How many rem is 12pt at the default 16px root?

12pt × (96÷72) = 16px. 16px ÷ 16px = 1rem. So 12pt = 1rem at the standard browser root font size.

What is the difference between pt, px, em, and rem?

pt (point) is an absolute unit: 1/72 inch. px is a screen pixel at 96 DPI. em is relative to the current element font size. rem is relative to the root ( ) font size. rem is preferred in web CSS because it scales with user preferences without compounding like em.

Does this converter work for print CSS?

The 96 DPI assumption applies to screen CSS. For print stylesheets, browsers render at 72 or 96 DPI depending on the UA — but rem units are rarely used in print CSS where pt and mm are more natural.

Points to rem Converter

Name: Points to rem Converter
Availability: InStock
Author: Nham Vu

Enter a point value and root font size to get the exact CSS rem equivalent instantly.

Convert Points to rem

Points (pt)

Root Font Size (px)

Default browser root font size is 16px.

Root Font Presets

Result

1 rem

12 pt × (96÷72) ÷ 16 = 1.000rem

Common Type Sizes

rem values update as you change the root font size.

Points (pt)	px (96 DPI)	rem (16px base)

Formula

rem = pt × (96 ÷ 72) ÷ rootFontSizePx

One point = 1/72 inch. At 96 DPI, 1pt = 96/72 ≈ 1.3333px. Divide by root font size to get rem.

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Summary

Enter a point value and root font size to get the exact CSS rem equivalent instantly.

How it works

Enter the number of typographic points (pt) to convert.
Set the root font size in pixels — default is 16px (browser default).
The tool computes: px = pt × (96 ÷ 72), then rem = px ÷ rootFontSizePx.
Use the root font size presets (10px, 16px, 18px) for common CSS configurations.
Copy the rem result or browse the reference table for common point sizes.

Use cases

Convert print or design tool point values directly to CSS rem for responsive layouts.
Match typographic point sizes from a design spec to accessible rem-based CSS.
Verify rem values when migrating print stylesheets to screen CSS.
Build a design token set by mapping standard type sizes (8pt, 10pt, 12pt…) to rem.
Calculate rem equivalents for a non-standard root font size such as 10px or 18px.
Cross-check point sizes between design software and a live CSS codebase.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu