Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Approximate Conversions from Metric to U.S. Customary Measures

The numerical value of the units in the When You Know column are multiplied by the approximate unit conversion factor found in the Multiply By column to obtain a numerical value for the units listed in the To Find Column. For example:

When You Know Multiply By To Find
20 m 1.09 approximately 21.8 yd


Symbol When You Know Multiply By To Find Symbol
mm millimeter 0.04 inch in
cm centimeter 0.39 inch in
m meter 3.28 foot ft
m meter 1.09 yard yd
km kilometer 0.62 mile mi



Symbol When You Know Multiply By To Find Symbol
cm² square centimeters 0.16 square inch in²
square meter 1.20 square yard yd²
km² square kilometer 0.39 square mile mi²
ha hectare
(10,000 m2)
2.47 acre  


Mass (weight)

Symbol When You Know Multiply By To Find Symbol
g gram 0.04 ounce oz
kg kilogram 2.20 pound lb
  metric ton
(1,000 kg)
1.10 short ton  



Symbol When You Know Multiply By To Find Symbol
mL milliliter 0.03 fluid ounce fl oz
mL milliliter 0.06 cubic inch in³
L liter 2.11 pint, liquid pt
L liter 1.06 quart, liquid qt
L liter 0.26 gallon gal
cubic meter 35.31 cubic foot ft³
cubic meter 1.31 cubic yard yd³


Temperature (exact)

Symbol When You Know Calculation To Find Symbol
°C degree Celsius multiply 1.8, then add 32 degree Fahrenheit °F
K Kelvin subtract 273.15 degree Celsius °C


U.S. Customary to Metric Conversions

Note: These approximate conversion factors are published as NIST SP 365, which is a laminated metric conversion card. Copies of this publication can be requested by contacting theSI [at] (theSI[at]nist[dot]gov)



Created January 13, 2010, Updated January 26, 2021