Conversion Units

Conversion Calculator

Metric Conversions
(* = exact relationship)

1 inch = 2.54cm*
1 foot = 0.3048 meters*
1 N. Mile = 1.852 Kilometres*
1 Pound = 0.4536 kilograms*
1 U.S. Gallon = 3.785 litres*

Navigational Chart Scales
Nautical miles/inch = reciprocal of natural scale - 72,913.39
Statute miles/inch...... = reciprocal of natural scale - 63,360*
Inches/nautical mile....= 72,913.39 X natural scale
Inches per stat. mile...= 63,360 X natural scale*
Natural scale........... = 1:72,913.39 X nautical miles per inch
= 1:63,360 X statute mile per inch*

Time and Space 1 mean solar unit.. = 1.00273791 sidereal units
1 sidereal unit.... = 0.99726957 mean solar unit
1 microsecond...... = 0.000001 second*
1 second...... = 1,000,000 microseconds*
= 0.01666667 minute
= 0.00027778 hour
= 0.00001157 day

1 minute...... = 60 seconds*
= 0.01666667 hour
= 0.00069444 day

1 hour........ = 3,600 seconds*
= 60 minutes*
= 0.04166667 day

1 mean solar day..... = 24h 03m 56s55536 of mean sidereal time
= 1 rotation of earth with respect to sun (mean)*
= 1.00273791 rotations of earth w/respect to Aries (mean)
= 1.0027378118868 rotations of earth w/respect to stars(mean)

1 mean sidereal day = 23h 56m 04s09054 of mean solar time

1 sidereal month........ = 27.321661 days
= 27d 07h 43m 11s5

1 synodical month....... = 29.530588 days
= 29d 12h 44m 02s8

1 tropical (norm) year.. = 31,556,925.975 seconds
= 525,948.766 minutes
= 8,765.8128 hours
= 365d.242198 -0d.0000000614(t-1900), where t = the year
= 365d 05h 48m 46s (-) 0s 0053t

1 sidereal year........ = 365d.25636042+0.0000000011(t-1900), where t = the year
= 365d 06h 09m 09s.5 (+) 0s.0001t

1 norm. calendar year... = 31,536,000 seconds*
= 525,600 minutes*
= 8,760 hours*
= 365 days*

1 calendar year (leap).. = 31,622,400 seconds*
= 528,040 minutes*
= 8,784 hours*
= 366 days*

1 light-year = 9,460,000,000,000 kilometers
= 5,880,000,000,000 statute miles
= 5,110,000,000,000 nautical miles
= 63,240 astronomical units
= 0.3066 parsecs

1 parsec..... = 30,860,000,000,000 kilometers
= 19,170,000,000,000 statute miles
= 16,660,000,000,000 NM
= 206,300 astronomical units
= 3.262 light years

1 astronomical unit..... = 149,600,000 kilometers
= 92,960,000 statute miles
= 80,780,000 nautical miles
= 499s.012 light-time
= mean distance, earth to sun

Mean dist. earth-moon... = 384,400 kilometers
= 238,855 statute miles
= 207,559 nautical miles

Mean distance earth to sun.... = 149,600,000 kilometers
= 92,957,000 statute miles
= 80,780,000 nautical miles
= 1 astronomical unit

Sun's dia. ... = 1,392,000 kilometer 
= 865,000 statute miles
= 752,000 nautical miles

Speed of sun relative to neighbouring stars.... = 19.4 kilometers per second
= 12.1 statute miles per second
= 10.5 nautical miles per second

Orbital speed of earth...... = 29.8 kilometers per second
= 18.5 statute miles per second
= 16.1 nautical miles per second

Obliquity of the ecliptic.. = 23º 27' 08".26 - 0".4684(t-1900), where t=the year

General precession of the equinoxes.... = 50".2564 + 0".000222(t-1900) per year, where t=the year

Precession of the equinoxes in right ascension.... = 46".0850 + 0".000279(t-1900) per year, where t=the year

Precession of the equinoxes in declination.. = 20".0468-0".000085(t-1900) per year, where t=the year

Magnitude ratio....... = 2.512
= 5th root of 100*
Angles degrees mils minutes radians seconds
Areas acre centimeter²(cm²) foot² hectare inch² kilometer² metre²(m²) mile² millimeter²(mm²) yard²
Energy & Temperature BTUs calorie ergs gigajoules gigawatt-hours horsepower-hours joules kilocalories kilojoules kilowatt-hours(kW-hr) megajoules megawatt-hours(MW-hrs) microjoules millijoules tons watt-hours

degrees Fahrenheit = (degrees Celsius X 1.8) + 32

degrees Celsius... = (degrees Fahrenheit - 32) X 0.5555556

1 calorie = amount of heat/energy to raise 1 kilo water 1 degree Centigrade
= 1000 calories (1 gram water 1 degree Centigrade)
= 3.968 British thermal units (BTU)

1 BTU..... = amount of heat/energy to raise 1 lb water 1degree Fahrenheit
= .2520161 calories
= 252.01613 calories
Flow centimetres³(cc/hr) gallons/hour gallons/hour(UK) litres/hour(l/hr)
Length centimeters fathoms feet inches kilometers(km) metres(m) micrometers micrometers miles millimeters nautical miles thousandths inches(0.001") yards

1 mill = 0.001 inches
= 0.0393701 microns
= .83333333 feet

1 inch = 25.4 millimeters*
= .027777778 yards
= 2.54 centimeters*
= 0.0254 meters

1 foot (U.S.) = 12 inches*
= 1 British foot
= 1/3 yard* (.33333333 yards)
= 0.3048 meter*
= 1/6 fathom* (.166666667 fathoms)

1 foot (U.S. Survey) = 0.30480061 meter

1 yard....... = 36 inches*
= 3 feet*
= 0.9144 meter*

1 league..... = 18,228.347 feet
= 3,038.0578 fathoms
= 3 nautical miles
= 3 minutes of latitude
= 5.556 kilometers
= 5,556 meters

1 fathom..... = 6 feet*
= 2 yards*
= 1.8288 meters*

1 cable (U.S.)...... = .1184968 nautical miles
= 720 feet*
= 1.1849676 British cables
= 120 fathoms
= 240 yards*
= 219.4560 meters*
= .1184968 nautical miles

 1 cable (British)... = 101.26859 fathoms
= 0.1 nautical mile
= .8469049 U.S. cables
= 07.61155 feet

1 statute mile........ = 5,280 feet*
= 1,760 yards*
= 1,609.344 meters*
= 1.609344 kilometers*
= 0.86897624 nautical mile

1 nautical mile........ = 6,076.11548556 feet
= 2,025.37182852 yards
= 1,852 meters*
= 1.852 kilometers*
= 1.150779448 statute miles

1 meter...... = 100 centimeters*
= 39.370079 inches
= 3.28083990 feet
= 1.09361330 yards
= 0.54680665 fathom
= 0.00062137 statute mile
= 0.00053996 nautical mile

1 kilometer.. = 3,280.83990 feet
= 1,093.61330 yards
= 1,000 meters*
= 0.62137119 statute mile
= 0.53995680 nautical mile
Power  horsepower(metric) horsepower(SAE) kilowatt(kW) megawatts milliwatt watt(W)
Pressures atmospheres bar inch mecury inch water kg/cm² kg/m² kilopascal megapascal millibar mm mecury mm water newton/m² pascal pound/inch²(psi or lbs-in²)

Standard atmospheric pressure at sea level...
= 1,013.250 dynes per SQ CM
= 1,033.227 grams per SQ CM
= 1,033.227 centimeters of water
= 1,013.250 milibars*
= 760 millimeters of mercury
= 76 centimeters of mercury
= 33.8985 feet of water
= 29.92126 inches of mercury
= 14.6960 pounds per SQ inch
= 1.033227 kilograms per SQ CM
= 1.013250 bars*

Absolute zero.
=  -273º.16C
=  -459º.69 F

PRESSURE
1 atmosphere..
= 33.8985 feet of water
= 29.92126 inches of mercury
= 14.6960 pounds per SQ inches
= 10.33227 meters of water
= 760 millimeters of mercury

1 dyne/SQ cm .
= .001 millibar*
= 0.000001 bar*

1 gram/SQ cm .
= 1 centimeter of water
= 0.980665 millibar*
= 0.07355592 CM of mercury
= 0.0289590 inch of mercury
= 0.0142233 pound per SQ inch
= 0.001 KG per SQ centimeter*
= 0.000967841 atmosphere

1 millibar....
= 1,000 dynes/SQ centimeter*
= 1.01971621 grams/SQ CM
= 0.7500617 millimeter mercury
= 0.03345526 foot of water 
= 0.02952998 inch of mercury
= 0.01450377 pound per SQ inch
= 0.001 bar*
= 0.00098692 atmosphere

Atmosphere Composition (dry air)
Nitrogen....... = 78.08%  
Oxygen......... = 20.95%
Carbon dioxide. = 0.0018%
Helium......... = 0.000524%
Krypton........ = 0.0001%
Hydrogen....... = 0.00005%
Xenon.......... = 0.0000087%
Ozone......... = 0 to 0.000007% (increasing with altitude)
Radon.......... = 0.000000000000000006% (decreasing with altitude)

 1 millimeter of mercury...
= 1.35951 grams/SQ centimeter
= 1.3332237 millibars
= .1 centimeter of mercury*
= 0.04460334 foot of water
= 0.039370079 inch of mercury
= 0.01933677 pound per SQ inch
= 0.001315790 atmosphere

1 centimeter of mercury....
= 10 millimeters of mercury*

1 inch of mercury....... = 34.53155 grams per SQ centimeter
= 3.86389 millibars
= 25.4 millimeters of mercury*
= 1.132925 feet of water
= 0.4911541 pound per SQ inch
= 0.03342106 atmosphere

1 centimeter of water...... = 1 gram per SQ centimeter
= 0.001 kilogram/SQ centimeter

1 foot of water......... = 30.48000 grams/SQ centimeter
= 29.89067 millibars
= 2.241985 CM of mercury
= 0.882671 inch of mercury
= 0.4335275 pound per SQ inch
= 0.02949980 atmosphere

1 pound per SQ inch....... = 68,947.57 dynes/SQ CM
= 144 pounds per SQ foot
= 70.30696 grams/SQ centimeter
= 0.30696 CM of water
= 68.94757 millibars
= 51.71493 MM of mercury
= 5.171493 CM of mercury
= 2.306659 feet of water
= 2.036021 inches of mercury
= 0.07030696 KG per SQ CM
= 0.06894757 bar

1 pound per SQ foot....... = 0.0069444 lbs per SQ in
= 0.0680460 atmospheres

1 kilogram per  SQ CM........
= 1,000 grams per SQ cm*
= 1,000 centimeters of water

1 bar.........
= 1,000,000 dynes per SQ centimeter*
= 1,000 millibars*
Speed

(* means exact relationships)

 feet/hour feet/min feet/sec kilometres per hour(km/hr) knots(kts) metres per hour(m/hr) metres per min(m/min) metres per second(m/sec) miles/hour miles/min miles/sec

1 knot........ 
= 101.26859143 feet per minute
= 33.75619714 yards per minute
= 1.852 kilometres per hour*
= 1.68780986 feet per second
= 1.15077945 statute MPH
= 0.51444444 meter per second

1 kilometer per hour...... 
= 0.62137119 statute mile per hour
= 0.53995680 knot

1 meter per second.... 
= 196.85039340 feet per minute
= 65.6167978 yards per minute
= 3.6 kilometers per hour*
= .28083990 feet per second
= 2.23693632 statute MPH
= 1.94384449 knots

Light in vacuum.... 
= 299,792.5 kilometers per second
= 186,282 statute miles per second
= 161,875 naut. miles per second
= 983.570 feet per microsecond

Light in air.. 
= 299,708 kilometers per second
= 186,230 statute miles per second
= 161,829 naut. miles per second
= 983.294 feet per microsecond

Sound in dry air at 59ºF or 15ºC and
standard sea level pressure...... 
= 1,116.45 feet per second
= 761.22 statute miles per hour
= 661.48 knots
= 340.29 meters per second

 1 foot per minute........
  = 0.01666667 foot per second
= 0.00508 meter per second*

1 yard per minute....... 
= 3 feet per minute*
= 0.05 foot per second*
= 0.03409091 statute mile per hour
= 0.02962419 knot
= 0.01524 meter per second*

1 foot per second........ 
= 60 feet per minute*
= 20 yards per minute*
= 1.09728 kilometers per hour*
= 0.68181818 statute mile per hour
= 0.59248380 knot
= 0.3048 meter per second*

1 statute mile per hour...... 
= 88 feet per minute*
= 29.33333333 yards per minute
= 1.609344 kilometers per hour*
= 1.46666667 feet per second
= 0.86897624 knot
= 0.44704 meter per second*

Sound in 3.485 % saltwater at 60ºF....... 
= 4,945.37 feet per second
= 3,371.85 statute miles per hour
= 2,930.05 knots
= 1,507.35 meters per second
Torque dyne-centimetre gram-centimetre kilogram-centimetre(kg-cm) newton-metre(nm) ounce-inch pound-foot(lb-ft) pound-inch(lb-in)
Volume centilitre(cl) centimetre³(cc or cm³) foot³ gallon gallon(UK) inch³(cu in) litre(l) metre³(m³) millilitre(ml) pint pint(UK) quart quart(UK)

1 fluid ounce = 0.03125 quarts
= 29.57353 cubic CM or milliliters

1 cubic inch. = 16.387064 cubic centimeters*
= 0.016387064 liter*
= 0.004329004 gallon

1 cubic foot. = 1,728 cubic inches*
= 28.316846592 liters*
= 7.480519 U.S. gallons
= 6.228822 Imp.(British) gallons 
= 0.028316846592 cubic meter*
= 0.037037 cubic yards

1 cubic yard. = 46,656 cubic inches*
= 764.554857984 liters*
= 01.974026 U.S. gallons
= 168.1782 Imp. (British) gallons
= 27 cubic feet*
= 0.764554857984 cubic meter*

1 milliliter. = 0.06102374 cubic inch
= 0.0002641721 U.S. gallon
= 0.00021997 Imp. (British) gallon

1 cubic meter = 264.172035 U.S. gallons
= 19.96878 Imp. (British) gallons
= 35.31467 cubic feet
= 1.307951 cubic yards

1 quart U.S. = 57.75 cubic inches*
= 32 fluid ounces*
= 2 pints*
= 0.9463529 liter
= 0.25 gallon*

1 gallon U.S. = 3,785.412 millititers
= 231 cubic inches*
= 128 fluid ounces
= 4 quarts*
= 8 pints
= 3.785412 liters
= 0.8326725 Imp. (British) gallon

1 liter...... = 1,000 millititers

= 61.02374 cubic inches
= 1.056688 quarts
= 0.2641721 gallon

1 register ton ........ = 100 cubic feet*
= 2.8316846592 cubic meters*

1 measurement ton......... = 40 cubic feet*
= 1 freight ton*

1 freight ton = 40 
= 1 measurement ton*

1 cubic foot of seawater. = 64 pounds

1 cubic foot of freshwater = 62.428 pounds at temp. of max density (4degreesC=39.2 degrees F)

1 cubic foot of ice.. = 56 pounds

1 displacement ton......... = 35 cubic feet of seawater*
= 1 long ton
Weights dynes grains grams hundredweights hundredweights(UK) kilograms(kg) milligrams ounces pounds stone(UK) stones tonnes(metric) tons tons(long) troy ounces

1 ounce...... = 437.5 grains*
= 28.349523125 grams*
= 0.0625 pound*
= 0.028349523125 kilogram*

1 pound...... = 7,000 grains*
= 16 ounces*
= 0.45359237 kilogram*

1 short ton.. = 2,000 pounds*
= 907.18474 kilograms*
= 0.90718474 metric ton*
= 0.8928571 long ton

1 long ton... = 2,240 pounds*
= 35 SQ feet of seawater
= 1,016.0469088 kilograms*
= 1.12 short tons*
= 1.0160469088 metric tons*

1 kilogram... = 2.204623 pounds
= 0.00110231 short ton
= 0.0009842065 long ton

1 metric ton. = 2,204.623 pounds
= 1,000 kilograms*
= 1.102311 short tons
= 0.9842065 long ton