Checked 15 October 2026. What was checked. How these pages are maintained.
Conversion factors
Length is converted through metres (1 ft = 0.3048 m, 1 in = 0.0254 m, 1 mi = 1609.344 m). Weight is converted through kilograms (1 lb = 0.45359237 kg, 1 oz = 1/16 lb, 1 stone = 14 lb). Temperature: C = (F − 32) × 5/9, K = C + 273.15.
Worked example
5 km is 3.107 miles. 180 lb is about 81.6 kg. 22 °C is 71.6 °F. 1 inch is defined as 25.4 mm; these conversions are exact on that definition, then rounded for display.
Cooking “cups” are not the same as a metric cup in every country. This page is length, weight, and temperature, not recipes.
Exact definitions, then a rounded display
Length passes through metres. One international foot is exactly 0.3048 m, so 10 feet is 3.048 m, 304.8 cm, and about 0.0019 miles. One inch is exactly 25.4 mm. One mile is exactly 1,609.344 m. Weight passes through kilograms. One pound is exactly 0.45359237 kg, so 150 lb is 68.039 kg on this page’s display. One stone is 14 lb, which is 6.35029318 kg. Temperature is not a ratio. Water does not freeze at 0 °F. The page uses °C = (°F − 32) × 5/9, so 72 °F is 22.22 °C and 295.37 K. Kelvin is Celsius plus 273.15.
The three blocks are independent. Changing feet does not change the pound box or the thermometer. Each block converts the value you typed into the other units in that family. You do not pick a “to” unit. The result lists several.
What is not on the page
Cups, tablespoons, and millilitres of a recipe are absent. A US cup and a metric cup are not the same, and this tool will not pretend they are a length. Currency is absent. A foot here is the international foot, not the older US survey foot, which differs at a level that matters to land surveyors and almost never to a room. If a running pace was calculated in miles and you want kilometres, convert the distance here and redo the pace on the pace calculator. Do not multiply a per-mile pace by 1.6 in your head and expect the seconds to come out clean. 5:30 per kilometre is not 5:30 × 1.6 in clock minutes without converting the seconds properly.
Common questions
Are these survey feet or international feet?
International feet (exact 0.3048 m), which is what almost every everyday conversion uses.
Why is stone on the list?
Common in the UK and Ireland for body weight. 1 stone = 14 pounds.