Modern Converts is a free unit converter covering 25 measurement categories and more than 4,400 unit pairs. It leans towards the quantities that general-purpose converters treat as an afterthought: volume flow rate, pressure, apparent power, torque, frequency and the other units that come up in engineering work. It has been online since 2025.
Modern Converts is an independent project, operated from Vietnam since 2025, with no advertiser, vendor or manufacturer behind it. That independence is the point: no unit, factor or definition here is chosen to favour a product. The unit table, the formulas, the reference checks and the explanatory text are all maintained under one roof, so a correction reported today ships in the next release rather than entering a ticket queue.
Every conversion is a chain of exact ratios to one anchor unit per category, computed with arbitrary-precision arithmetic and rounded only when displayed. Before each release an automated check compares a set of factors with NIST Special Publication 811 and IEC 80000-13; the same table is published, live, on the methodology page, together with the definitions the site uses where more than one exists (US gallon, thermochemical calorie, international acre).
Conversions run in your browser. There are no accounts and no forms; the site only collects the aggregate usage statistics described in the privacy policy.
Found a wrong factor, a broken page or a misleading explanation? Email [email protected] with the page URL. Corrections ship in the next deployment.