Debugging a rem value
A 1.5rem margin resolves to 24px at the default root size.
Use rem to px
Converts rem to pixels in this tab, with nothing sent anywhere.
Runs entirely on your deviceThe conversion happens in this browser tab. Nothing you type is uploaded, logged or stored, which is worth knowing for anything you would not paste into a search box.
A 1.5 rem margin resolves to 24 px with a 16 px root. Users can enlarge their default text and sites can redefine the root size, which is precisely why rem values should not be treated as permanently fixed pixels.
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Browse all general convertersAbout rem to px
Reading a stylesheet written in rem, a developer often wants the pixel value it resolves to - to match a design, to debug spacing, or to reason about actual sizes. Converting rem to pixels multiplies by the root font size. At the 16px default, 1rem is 16px, 1.5rem is 24px and 0.75rem is 12px, the concrete sizes a browser will render. When a component looks wrong, resolving its rem values to pixels is often the fastest way to see whether the root font size, not the component, is the thing that has changed. Email templates, which cannot rely on rem, need pixel values, so a rem-based web spec is converted before it can be reused in an HTML email. A user font-size preference can change the rendered pixel size of rem-based spacing. For example, 2rem resolves to 32px at a 16px root and 40px at a 20px root; the same stylesheet can produce both.
Using rem to px
- Type a number of rem. You can paste a value with its unit; the tool reads the number.
- The exact factor is applied and the result is shown as px, updating live as you type.
- Copy the answer, or switch to the reverse converter to go from px back to rem.
Where rem to px helps
Both directions
Need the opposite? The px-to-rem converter is linked below and uses the exact inverse factor.
Nested font sizes do not change rem's reference
A 2 rem gap resolves to 32 px with a 16 px root even if the surrounding component uses a 12 px font size. That differs from em, which can depend on the element's font context. When a result differs from the browser, inspect the root's computed font size first, followed by zoom and any overridden CSS declaration.
Before you use the result
- The result is rounded for readability, so a value converted and then converted back may differ in the last decimal place. The underlying factor is exact.
- Units in your input are ignored - only the number is read - so make sure the figure you type is really in rem.
Questions about rem to px
Why might my rem not equal 16px?
Because rem is relative to the root font size. If the page sets html { font-size } to something other than 16px, multiply by that value instead.
Is my data uploaded?
No. rem to px does the arithmetic in this browser tab; the value is calculated on your device and is not sent to a server.
Related tools
px to rem
Convert px to rem instantly in your browser. Exact factor, both directions, nothing uploaded.