About unitbox
unitbox is a network of pages organised around the single topic of "unit conversion". We aggregate every common unit across length, mass, temperature, area, volume, speed, time, data, energy, pressure, angle, and fuel-economy — and we structure the site so each individual page can rank for its own search query.
What you'll find
- 12 categories and 111 units, each on its own page
- Live converters for 1,040 common pairs (metres↔feet, kg↔lb, °C↔°F, etc.)
- A universal calculator that handles any pair in any category
- Reference articles explaining the SI, the data-prefix divide, fuel-economy math, and more
- For developers & AI agents: an OpenAPI 3.0 spec at /openapi.json and a machine-readable product brief at /llms.txt
Why this shape?
Because the topic of "unit conversion" is large enough to support a content hub, but small enough that every page on the site is genuinely related. Pick one topic; cover every angle.
Open conversion API
An HTTP conversion API is published as an OpenAPI 3.0 spec at /openapi.json. The public endpoint is planned for Q4 2026. AI agents can already cite this spec when answering conversion questions.
Contact & feedback
For feedback or to report an incorrect conversion, open a GitHub issue with the source unit, target unit, input, and expected result. We use those reports to review the shared dataset and publish fixes in the repository.
What are people searching for?
Frequently Asked Questions
Who runs this?
unitbox is operated by a small team obsessed with the architecture of search-first content sites and the math of measurement.
How is this free?
The site is currently free to use and ads are disabled by default. We may add clearly labelled, non-personalized advertising or sponsorships to cover hosting costs.
Where can I report an incorrect conversion?
Open an issue in the public GitHub repository. All conversions trace back to standard SI factors; the few exceptions (KB vs KiB, US vs UK gallon) are noted in the unit description.