Contact us
Questions, corrections and requests all reach the same inbox, and we read every one. Use the form below and we will reply to the address you give us.
A number looks wrong
Tell us the two units and the value you expected. Conversion factors are the whole product, so we treat these first.
A missing unit or category
Regional land units, trade units and industry-specific measures are exactly the sort of thing we want to add.
Partnerships and press
Embedding a converter, licensing the data, or writing about the site — get in touch.
Response time
Usually within two working days. Corrections to conversion factors are prioritised and shipped as soon as they are verified against the SI and NIST definitions.