Clamp() Function Calculator

This advanced user-friendly CSS fluid responsive clamp() function calculator helps you create fluid, responsive values that seamlessly adapt to any screen size. Bookmark it, because you may need to use it over and over again!

CSS Clamp Calculator

  1. Root Font Size Selector:
    Control your scaling by setting a custom root font size (e.g., 100% or 62.5%). This ensures your layout remains consistent across various devices.
  2. Customizable Viewport Range:
    Define minimum and maximum viewport widths – for example 320px to 1366px – and let my calculator do the heavy lifting to achieve pixel-perfect scaling. 
  3. Target Value Inputs:
    Set the smallest and largest values you need (e.g., 1rem to 3rem). Our tool computes the ideal clamp() expression to automatically transition between these sizes.

Root Font Size

Viewport Range

px
px

Target Values

rem
rem

Your clamp() function

clamp(0rem, 0vw + 0rem, 0rem)

Understanding CSS Clamp() Function

The CSS clamp() function is a powerful tool for creating responsive designs. It allows you to set a value within a specific range, ensuring that it doesn’t go below a minimum or above a maximum value. This is particularly useful for spacing, typography, dimensions as it enables you to create a fluid typography system that adapts to different viewport widths.

To use the clamp function, you need to specify your root font size in percentages, either 100% or 62.5%, viewport range in pixels and target values in rem.

The CSS clamp() function allows you to specify a minimum, a preferred (or fluid) value, and a maximum size for any CSS property.

CSS Clamp() Function Example

font-size: clamp(1.75rem, 0.382vw + 1.674rem, 2rem);
  • Minimum Value (1.75rem): Ensures your text never shrinks below this size.
  • Preferred Value (0.382vw + 1.674rem): Ties your text size to the current viewport width, making it fluid.
  • Maximum Value (2rem): Caps the size so it doesn’t grow beyond a comfortable limit.

This powerful function helps maintain a balanced layout on all screens – from mobile devices to widescreen monitors.

Explaining how the clamp calculator scales text
Screenshot of the Clamp Calculator UI showing root font size selection

CSS Clamp() Function Explained

Scenario: You want your padding text to scale smoothly from 0.75rem at 320px to 1.15rem at 1366px, with a root font size of 100%. This means 1rem = 16px.

Generated clamp() Expression

clamp(0.75rem, 0.612vw + 0.628rem, 1.15rem)

Generated clamp() Implementation

.navigation {
    padding-top: clamp(0.85rem, 0.459vw + 0.758rem, 1.15rem);
    padding-bottom: clamp(0.85rem, 0.459vw + 0.758rem, 1.15rem);
}

Overall, the clamp() function ensures that your top and bottom padding scale responsively between 0.85rem and 1.15rem based on the user’s viewport width, creating a smooth and visually consistent layout across devices.