Free CSS Clamp calculator with clear step-by-step results.
Fluid typography is a straight line between two points: minimum size at the small viewport and maximum size at the large one. Solving for the slope gives the vw coefficient and the intercept gives the fixed rem term, which is what makes the value scale smoothly while remaining clamped at both ends.
Slope
vw coefficient = (max font - min font) / (max viewport - min viewport) x 100
Intercept
rem intercept = (min font - slope x min viewport) / root font size
A rem intercept keeps the text responsive to the user's browser font-size preference. A pure px and vw combination ignores that setting and is an accessibility failure.
No. The clamp itself pins the value at both ends, so the same declaration covers every viewport without breakpoints.