CM EM PX Converter

About This Tool

The tool performs bidirectional conversions between centimeters (cm), CSS pixels (px), and relative units (em). It accepts a numeric value, a source unit, and a target unit, and returns the converted value with standard rounding rules.
The logic normalizes the input to a base reference (px) and then re-scles to the target unit. For em units, a baseline font size (default 16px) defines the pixel value of 1em. For cm, a fixed px-per-cm mapping (96 DPI approximations) is used.
Who benefits include frontend developers, UI designers, print designers, and learners who require quick, auditable conversions during design-to-code handoffs or typography planning. The tool emphasizes deterministic results, traceable inputs, and clear outputs for reuse in CSS, print specs, and style guides. Core features include single-value input, unit-compatibility checks, baseline handling for em, and configurable precision. Optional features cover batch-like sequencing of targets, forced integer outputs, and export-ready strings.
Use cases span converting a responsive breakpoint size from px to em, translating print measurements in cm to CSS-friendly units, and verifying layout relationships across media.

Sign in to see all your usage