Conversions you can check
A unit converter is only useful if you trust the number it gives you. Every converter here shows the formula it used and the exact conversion factor, so you can verify the result by hand or quote it in a document.
The factors come from the international definitions rather than rounded shortcuts. One inch is exactly 25.4 millimetres, one pound is exactly 0.45359237 kilograms, and temperature conversions use the full formula rather than the rough "double it and add thirty" approximation.
Every page also carries a reference chart of common values you can read at a glance or print. Nothing here calls a server, so the answer appears as you type, even with no connection.
