Unit and Format Converter

About This Tool

This tool provides precise conversions between typography-related units (px, em, rem, pt) and standard length units (in, cm, mm) as well as basic document-format indicators (PDF points). It enables consistent sizing for CSS, print layouts, and export workflows. Conceptually, conversions are performed by normalizing to a base length (inches) using established mappings (pt = 1/72 in, px ≈ 1/96 in) and then re-expressing the value in the target unit. For em and rem, the converter derives the value from the current or root font size, expressed in pixels, to maintain proportional scaling. SI prefixes (pfx) are supported by applying standard multipliers (k, M, G) before normalization, enabling quick scaling of large or small values. The tool supports optional inputs for font size (font_size_px) and root font size (root_font_size_px) to handle typography-specific calculations. This approach benefits UI/UX designers coordinating on-screen and print sizes, frontend developers aligning CSS with print specs, and publication teams producing consistent PDFs. Unique value lies in integrating typography and document format considerations into a single, auditable conversion workflow with explicit handling of em/rem relationships and SI prefixes. Use cases include converting a 24px font-size to em for a 16px base, translating 2.5 in to mm for a poster, and exporting a set of values for a style guide in CSV or JSON.

Sign in to see all your usage