Enter a volume, pick its unit, and instantly see it in every other unit — metric, US customary, and imperial. US and imperial measures are clearly separated (an imperial pint is not the same as a US pint). Everything runs entirely in your browser.
US vs imperial: US and imperial units share names but differ in size — 1 imperial gallon ≈ 4.546 L while 1 US gallon ≈ 3.785 L. Metric units (millilitre, litre, cubic centimetre, cubic metre) are universal. Cups, ounces, and spoons here use US customary values.