CSS clamp calculator

Create a fluid CSS size rule.

On your device · No account

Privacy details

CSS clamp calculator processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

Your input

Options and local file

Maximum size (px)

Minimum viewport width (px)

Maximum viewport width (px)

Open a text file on this device

Optional settings apply only to this tab.

Your result

Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.

Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.

Keyboard shortcuts

Updated 2026-09-20

CSS clamp calculator explained

Create a clamp() expression from two size and viewport pairs. The middle term follows a straight line; the minimum and maximum cap the result outside the chosen range.

Next: PX to REM converter

Next: CSS specificity calculator

A worked example

16px at a 400px viewport and 32px at 1200px produce clamp(16px, 8px + 2vw, 32px). At an 800px viewport, the result is 24px.

Before you use the result

Generates a pixel-based rule rounded to six decimal places. Review text resizing and your layout at zoomed sizes; this arithmetic does not establish accessibility or a fit for every typeface.

Cite this page

Citation style

ToolOctopus. “CSS clamp calculator.” Updated 2026-09-20. https://tooloctopus.com/css-clamp-calculator.

Add an access date if your instructions require one.

Citation formatting uses citeproc-js by Frank Bennett and Citation Style Language styles. Licence and source code.