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Trail Construction and Maintenance Notebook

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Metric Conversions

To Convert From This Unit To This Unit Multiply by
inch millimeter 25.4*
inch centimeter 2.54*
foot meter 0.3048*
yard meter 0.9144*
mile kilometer 1.6
millimeter inch 0.039
centimeter inch 0.394
centimeter foot 0.0328
meter foot 3.28
meter yard 1.09
kilometer mile 0.62
acre hectare (sq. hectometer) 0.405
square kilometer square mile 0.386*
hectare (sq. hectometer) acre 2.47
ounce (avoirdupois) gram 28.35
pound (avoirdupois) kilogram 0.45
ton (2,000 pounds) kilogram 907.18
ton (2,000 pounds) megagram (metric ton) 0.9
gram ounce (avoirdupois) 0.035
kilogram pound (avoirdupois) 2.2
megagram (metric ton) ton (2,000 pounds) 1.102
ounce (U.S. liquid) milliliter 30
cup (inch-pound sys) milliliter 247
cup (inch-pound sys) liter 0.24
gallon (inch-pound sys) liter 3.8
quart (inch-pound sys) liter 0.95
pint (inch-pound sys) liter 0.47
milliliter ounce (U.S. liquid) 0.034
liter gallon 0.264
liter quart 1.057
degrees Fahrenheit degrees Celsius (°F - 32) x 1.8
degrees Celsius degrees Fahrenheit (°C x 1.8) + 32
*These items are exact conversion factors for the units [the others give approximate conversions]

Metric Comparisons

  • A millimeter, which is one-thousandth of a meter, is about the thickness of a dime.
  • One inch is just a fraction (1/64 inch) longer than 25 mm (1 inch = 25.4 mm).
  • 150 mm is the length of a dollar bill.
  • One foot is about 3/16 inch longer than 300 mm (12 inches = 304.8 mm).
  • A meter is a little longer than a yard, about a yard plus the length of a piece of chalk.

1 km (about 5/8 of a mile)

1 mile

Contract and Ordering Information

For additional information about trail construction and maintenance, contact Brian Vachowski at MTDC:

You can order a copy of this document using the order form on the FHWA's Recreational Trails Program web site at:

Fill out the order form and fax it to the distributor listed on the form. If you do not have internet access, you can send a fax request to 301-577-1421, e-mail your request to:, or request by mail from:

USDOT, Federal Highway Administration
Office of Human Environment
Rm. 3240 400 7th St. SW.
Washington, DC 20590

Produced by:

USDA Forest Service
Missoula Technology and Development Center
5785 Hwy. 10 West
Missoula, MT 59808-9361
Phone: 406-329-3978
Fax: 406-329-3719

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Table of Contents
Forest Service Technology & Development logo
Updated: 4/14/2014
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