Measurement Unit Converter

Instructions: Enter a number in the left-hand text box in any of the sections, and click on a unit in the left ("from") and/or right ("to") list boxes.  A new result appears in the right-hand text box whenever the input value (left-hand box) or either of the unit selections is changed.  Use the "Jump to" links above the section headings to navigate to the sections for different measurement types.  Conversion is done using JavaScript floating-point math and the most accurate factors I could find.  Certain results will have obvious (but very small) inaccuracies.  Results are rounded as you choose using the radio buttons below.  For unit info, see the dictionary of Units of Measurement at UNC and the US Law on Weights and Measures.

 

Please select the number of decimal places shown in results:

All (no rounding)  7
Jump to:   Length | Area | Weight | Volume | Energy | Force | Power | Pressure | Speed | Prefixes
 

Temperature Conversion

Convert 

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Note: For temperatures only, results are rounded to two decimal places.  The Rankine scale (proposed in 1859 by the Scottish physicist William J. M. Rankine) has the same degree units as Fahrenheit, but with zero = absolute zero.  The Reaumur scale (invented in 1730 by French naturalist René Antoine Ferchault de Reaumur) has 0 = the freezing point of H2O and 80 = the boiling point.

Jump to:   Temperature | Area | Weight | Volume | Energy | Force | Power | Pressure | Prefixes
 

Length / Distance Conversion

Convert 

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Note: in survey measure, a square link = 1/100,000 acre, so a link = 0.66 foot.  An engineer's link = 1 foot.   The span (arbitrarily) used here is nine inches and the cubit 18 inches.   The enormous Hubble unit (one billion light years or 306.595 megaparsecs) is not included here due to size constraints.  FYI, one hubble = about 9.4605 yottameters.

 Jump to:   Temperature | Length | Weight | Volume | Energy | Force | Power | Pressure | Prefixes
 

Area Conversion

Convert

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Note: There are many other old units of land area, such as the South Asian 'bigha' (~.33 acre), the English 'bovate' (~15 ac.) and 'hide' (about 120 ac.), the Dutch 'bunder' (now 1 hectare), the Spanish 'cabellaria' (about 40 ha.), the Irish 'colpa/collop' (~.6555 ha.) and acre (~1.6 English ac.), the Russian 'dessiatina' (1.0925 ha.), the Middle-Eastern 'dunum' (~.1 ha.), the North African 'feddan' (~.42 ha.), the old French 'journal' (~.3-.45 ha.), the Swedish 'tunnland' (~.493 ha.) and numerous others.

 Jump to:   Temperature | Length | Area | Volume | Energy | Force | Pressure | Power | Prefixes
 

Weight Conversion

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 Jump to:   Temperature | Length | Area | Weight | Energy | Force | Pressure | Power | Speed | Prefixes
 

Volume Conversion

Convert

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Apoth.: Apothecaries' | Avdp.: Avoirdupois | Brit.: British | Imp.: Imperial | Ship.: Shipping | Sur.: Survey

Note: U.S. and state legal definitions of a 'barrel' range from 31 to 42 gallons. 'Liter' is actually a special name for the cubic decimeter.

 Jump to:   Temperature | Length | Area | Weight | Volume | Force | Pressure | Power | Speed | Prefixes
 

Energy Conversion

Convert

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Note: BTU=British Thermal Unit. A watt is simply a joule per second. Calories/Kcal are the "IT" standard of 1956.

 Jump to:   Temperature | Length | Area | Weight | Volume | Energy | Pressure | Speed | Prefixes
 

Force Conversion

Convert

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Note: The pound force (lbf) unit represents the force exerted by Earth gravity on a mass of one pound.   The poundal is defined as a force which accelerates a one-pound mass at the rate of one foot per second.

 Jump to:   Temperature | Length | Area | Weight | Volume | Force | Energy | Pressure | Speed | Prefixes
 

Power Conversion

Convert

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Note: The metric horsepower is known in France as the "Cheval Vapeur" (CV) and in Germany as the "pferdestärke". The horsepower, btw, was defined by James Watt as 550 lbf/sec.  

 Jump to:   Temperature | Length | Area | Weight | Volume | Energy | Force | Speed | Prefixes
 

Pressure Conversion

Convert

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 Jump to:   Temperature | Length | Area | Weight | Volume | Energy | Force | Power | Speed
 

Metric-System Prefixes

Prefix Abbr. Meaning Prefix Abbr. Meaning
yottaY1024 (septillion) yoctoy1/1024
zettaZ1021 (sextillion) zeptoz1/1021
exaE1018 (quintillion) attoa1/1018
petaP1015 (quadrillion) femtof1/1015
teraT1012 (trillion) picop1/1012
gigaG109 (billion) nanon1/109
megaM106 (million) microµ1/106
kilok1000 millim1/1000
hectoh100 centic1/100
dekada10 decid1/10
(Most conversion factors are from the tables at the U.S. National Institute of Standards and Technology.)
Please see UNC Prof. Russ Rowlett's Dictionary of Units of Measurement for comprehensive(!!) info on measurement units & systems and links to many related sites.

Created by Rick Fleming, University of Virginia