About Clampcraft

A small tool for an inspectable rule.

Clampcraft turns two selected viewport/font-size anchors into one bounded CSS declaration. It is designed for a person who already has a reason for the endpoint sizes and wants to check the arithmetic between them.

One relationship, explained

The calculator keeps the anchor model exact using integer fractions. It then produces a practical decimal CSS declaration, a sample-width answer and a small width table. Increasing, decreasing and constant cases belong in the same calculator because they are the same underlying relationship.

The output does not select a font, inspect your design or edit a live site. The browser preview applies the result to one visible line here; it is separate from the numerical sample. Your own font, content, zoom settings and layout still need testing.

Free and browser-local

There is no account, payment or upload step. Calculation runs in this page after it loads. Copying uses the browser clipboard only when you choose it, and downloaded notes are generated on your device. This release contains no advertising or analytics loader.

Accuracy with a clear boundary

Exact fractions are shown alongside rounded displays. The CSS export uses at most twelve decimal places for non-terminating coefficients. Browser precision and font rendering are separate matters; the tool makes no accessibility or universal compatibility claim. The guide explains the limits and provides original checkable examples.

If you find a wrong result or unclear instruction, the contact page explains how to send a useful compact example. Reports can help improve this focused tool; no response time is promised.