How to use this tool
Choose a measurement family, a value and two units from that family. Length, mass and time use fixed conversion factors through a base unit. Temperature uses an affine conversion, because Fahrenheit and Celsius have different zero points. Time units are fixed durations: a day is 24 hours and a week is seven such days. Calendar months are not included.
Try these values
1 inch is exactly 2.54 centimeters. 1 pound is exactly 0.45359237 kilograms. 0 °C is 32 °F, and 100 °C is 212 °F. A duration of 90 minutes is 1.5 hours.
Keep the measurement family consistent
Choose length, mass, temperature or a fixed duration before selecting the units. Kilograms cannot be converted directly to meters, and a calendar month cannot be treated as a fixed number of hours. Some familiar words also have regional meanings, especially for volume. This converter leaves those ambiguous volume units out rather than quietly choosing a US or imperial definition for you.
Temperature uses a different kind of formula
For most units here, conversion is multiplication by a factor. Temperature also needs a shift in the zero point: zero Celsius is thirty-two Fahrenheit, not zero Fahrenheit. Kelvin starts at absolute zero, so a value below zero kelvin is rejected. The displayed result is rounded for readability; use the exact factor stated in the example when you need to check an intermediate calculation.
Common questions
Can I convert months to days?
No. Calendar months have different lengths. Use the date duration calculator for that question.
Are these US or imperial units?
Length and mass units use the international inch, foot, yard, mile, ounce and pound. Volume units are omitted to avoid regional ambiguity.
Can temperatures be below absolute zero?
No. Values below 0 kelvin are rejected.
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