Mass

• 1 pound = 453.6 grams

• 1 grain = 64.798 milligrams
• 1 dram = 1.772 grams
• 1 ounce = 16 drams
• 1 dram = 27.344 grains
• 1 pound = 7,000. grains
• 1 ton = 2000 pounds
• 1 metric ton = 1000 kilograms

Length

• 1 inch = 2.54 centimeters (exact)

• 1 foot = 12 inches
• 1 yard = 3 feet
• 1 rod = 5.5 yards
• 1 mile = 5280 feet
• 1 nautical mile = 1.852 kilometers
• 1 furlong = 220 yards
• 1 meter = 10³ millimeters
• 1 meter = 10² centimeters
• 1 meter = 10⁹ nanometers

Volume

• 1 gallon = 3.785 liters
• 1 milliliter = 1 cubic centimeter

• 1 fluid ounce = 8 fluid drams
• 1 fluid ounce = 29.573 milliliters
• 1 pint = 16 fluid ounces
• 1 quart = 2 pints
• 1 gallon = 4 quarts
• 1 barrel = 42 gallons
• 1 tablespoon = 3 teaspoon
• 1 fluid ounce = 2 tablespoon
• 1 cup = 8 fluid ounces
• 1 pint = 2 cups
• 1 cubic yard = 27 cubic feet
• 1 megaliter = 10⁶ liters
• 1 liter = 10⁶ microliters

Area

• 1 acre = 43,560 square feet
• 1 square mile = 640 acres
• 1 square foot = 144 square inches

Time

• 1 century = 100 years
• 1 year = 365.25 days
• 1 day = 24 hours
• 1 hour = 60 minutes
• 1 minute = 60 seconds
• 1 second = 10¹² picoseconds