Appendix E—Useful Formulas

Length Conversions

to miles (mi) = km × 0.62

= nmi÷1.151

= ft÷5,280

to kilometers (km) = mi × 1.61

= nmi×1.852

= ft÷3,281

to nautical miles (nmi) = mi ÷ 1.51

= km÷1.852

= ft÷6,076

to feet (ft) = mi × 5,280

= km×3,281

= nmi×6,076

Area Conversions

to square miles (mi²) = km² ÷ 2.59

= nmi² × 1.324

to square kilometers (km²) = mi² × 2.59

= nmi² × 3.43

to square nautical miles (nmi²) = mi² ÷ 1.324

= km² ÷ 3.43

Volume Conversions

to gallons (gal) = m³ × 264.2

= L÷3.785

to cubic meters (m³) = gal ÷ 264.2

= L÷1,000

to liters (L) = gal × 3.785

= m³ × 1,000

Pressure Conversions

to atmospheres (atm) = mb ÷ 1,013

= in. Hg÷29.92

= lb/in² ÷ 14.7

= Pa÷101,300

to millibars (mb) = atm × 1,013

= in. Hg×33.864

= lb/in² × 68.948

= Pa÷100

to inches of Mercury (in. Hg) = atm × 29.92

= mb÷33.864

= lb/in² × 2.036

= Pa÷3,386

to Pascals (Pa) = atm × 101,300

= mb×100

= in. Hg×3,386

= lb/in² × 6,895

Speed Conversions

to miles per hour (mph) = knots × 1.151

= km/hr÷1.609

= ft/s÷1.467

= m/s×2.237

to nautical miles per hour (knots) = mph ÷ 1.151

= km/hr÷1.852

= ft/s÷1.688

= m/s×1.944

to kilometers per hour (km/hr) = mph × 1.609

= knots×1.852

= ft/s×1.097

= m/s×3.6

to feet per second (f/s) = mph × 1.467

= km/hr÷1.097

= knots×1.688

= m/s×3.281

to meters per second (m/s) = mph ÷ 2.237

= knots÷1.944

= km/hr÷3.6

= ft/s÷3.281

Temperature

To convert degrees Fahrenheit (°F) to degrees Celsius (°C): (°F – 32) ÷ 1.8

To convert degrees Celsius (°C) to degrees Fahrenheit (°F): (°C × 1.8) + 32)