Web DevelopmentGenerated accuracy model review: 2026-05-06

Fluid Type accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

The formula calculates the slope (rate of change) between the two font sizes over the two viewport widths. It produces a `clamp(MIN, PREFERRED, MAX)` value where PREFERRED is a combination of REM and VW units.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

Min Viewport: 320 px
Max Viewport: 1,200 px
Min Font Size: 16 px
Max Font Size: 24 px

Expected outputs

CSS Clamp: font-size: clamp(1.000rem, 0.818rem + 0.909vw, 1.500rem);

Known limitations

This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

The output assumes a 16px root font size when converting the min, max, and intercept values into REM.
Viewport widths and font sizes should describe a sensible increasing range for the fluid formula to be useful.
The generated rule targets font sizing specifically, even though the same `clamp()` pattern can be adapted for spacing.

Unit handling

Min Viewport accepts values in px.
Max Viewport accepts values in px.
Min Font Size accepts values in px.
Max Font Size accepts values in px.

Rounding rules

Number displays use up to 2 decimal places in the calculator UI.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current fluid-typography-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Fluid Type.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

Use calculator