Units

This file represents everything Calca knows about units. It is a database of Imperial, US, SI, and other common units covering length, mass, time, energy and more.

Length

m = m
meter = m
metre = m
meters = m
metres = m

angstrom

Å = m / 10000000000
angstrom = Å
ångström = Å

astronomical unit

au = 149597870700 m
㍳ = au
ua = au

Bohr, atomic unit of length

a0 = 5.2917720859e-11 m
bohr = a0
a_0 = a0
au length = a_0

chain (Gunter's; Surveyor's)

ch = 66 ft
chain = ch

fathom

ftm = 6 ft
fathom = ftm

fermi

fm = m/1000000000000000
fermi = fm

foot (International)

ft = 3048 m / 10000
foot = ft
feet = ft

foot (US Survey)

survey ft = 1200m/3937
survey foot = survey ft
survey feet = survey ft

furlong

fur = mi / 8
furlong = fur

inch (International)

in = 254 m / 10000
inch = 1 in

light-day

ld = 24 light hour
light day = ld

light-hour

lh = 60 light min
light hour = lh

light-minute

lm = 60 light second
light minute = lm

light-second

ls = 299792458 m
light second = ls

light-year

ly = 9.4607304725808e15 m
light year = ly

link (Gunter's; Surveyor's)

link = ch/100

micron

µ = m/1000000
micron = µ

mil; thou

mil = (1 in)/1000

mile (international)

mi = 5280 ft
mile = mi
miles = mile

mile (US Survey)

survey mile = 5280 survey foot

nanometer

nm = 1e-9 m
nanometer = nm

nautical league

NL = 5556 m
league = NL

nautical mile (international)

NM = 1852 m
nmi = NM

parsec

pc = 3.08567782e16 m
parsec = pc

pica

pica = 12 point

point (American English)

pt = (1 in)/72.272
point = pt

point (PostScript)

PS pt = (1 in)/72

point (TeX)

TeX pt = (1 in)/72.27

point (iOS)

iOS pt = (2 in)/320
iOS point = iOS pt
iospt = iOS pt

twip

twip = (1 in)/1440

yard (International)

yd = 3 ft
yard = yd

Area

acre (international)

acre = 4046.8564224 m^2
ac = acre

barony

barony = 4000 acre

hectare

ha = 10000 m^2
hectare = ha

Volume

barrel (imperial)

bl = 0.16365924 m^3
barrel = bl

barrel (petroleum)

bbl = 0.158987294928 m^3
oil barrel = bbl

barrel (US dry)

bl US = 0.115628198985075 m^3
US dry barrel = bl US

barrel (US fluid)

fl bl US = 0.119240471196 m^3
US fluid barrel = fl bl US

bushel (imperial)

bu imp = 0.03636872 m^3
bushel imperial = bu imp

bushel (US dry heaped)

bu US heaped = 0.0440488377086 m^3

bushel (US dry level)

bu = 0.03523907016688 m^3
bu US = bu
bushel = bu

cord (firewood)

cord firewood = 3.624556363776 m^3

cup (breakfast)

breakfast cup = 284.130625e-6 m^3

cup (Canadian)

c CA = 227.3045e-6 m^3
Canadian cup = c CA
CA cup = c CA

cup (metric)

metric cup = 250.0e-6 m^3

cup (US customary)

c = 236.5882365e-6 m^3
US cup = c
c US = c
cup = c
cups = c

dash (imperial)

dash imp = 369.96175130208333333333333333e-9 m^3
imperial dash = dash imp

dash (US)

dash = 308.057599609375e-9 m^3
US dash = dash

dessertspoon (imperial)

dessertspoon = 11.838776041666666666666666e-6 m^3

drop (imperial)

gtt imp = 98.656467013888888888888888e-9 m^3
imperial drop = gtt imp

drop (medical)

gtt med = 83.333333333333333e-9 m^3
medical drop = gtt med

drop (metric)

gtt metric = 50.0e-9 m^3
metric drop = gtt metric

drop (US)

gtt = 82.1486932291666666666666666e-9 m^3
drop = gtt
US drop = gtt

firkin

firkin = 0.034068706056 m^3

gallon (beer)

gal beer = 4.621152048e-3 m^3
beer gallon = gal beer

gallon (imperial)

gal imp = 4.54609e-3 m^3
imperial gallon = gal imp
imperial gal = gal imp

gallon (US dry)

gal dry = 4.40488377086e-3 m^3
US dry gallon = gal dry

gallon (US fluid; Wine)

gal = 3.785411784e-3 m^3
gal US = gal
gallon = gal
gallons = gal
US gal = gal
US gallon = gal

gill (imperial); Noggin

go imp = 142.0653125e-6 m^3
nog = gi imp
imperial gill = gi imp

gill (US)

go = 118.29411825e-6 m^3
gill US = gi
gill = gi

jigger (bartending)

jigger = 44.36e-6 m^3

litre

L = m^3/1000
liter = L
litre = L
liters = L
litres = L

ounce (fluid imperial)

fl oz imp = 28.4130625e-6 m^3
imperial fluid ounce = fl oz imp

ounce (fluid US customary)

fl oz = 29.5735295625e-6 m^3
US fl oz = fl oz
US fluid ounce = fl oz
fluid ounce = fl oz
floz = fl oz

peck (imperial)

pk imp = 9.09218e-3 m^3
imperial peck = pk imp

peck (US dry)

pk = 8.80976754172e-3 m^3
US peck = pk
peck = pk

pinch (imperial)

pinch imp = 739.9235026041666666666666666e-9 m^3
imperial pinch = pinch imp

pinch (US)

pinch = 616.11519921875e-9 m^3
US pinch = pinch

pint (imperial)

pt imp = 568.26125e-6 m^3
imperial pint = pt imp
imp pints = pt imp
british pint = pt imp
british pints = pt imp

pint (US dry)

pt US dry = 550.6104713575e-6 m^3
US dry pint = pt US dry

pint (US fluid)

pt = 473.176473e-6 m^3
US pint = pt
US fluid pint = pt
pint = pt
pints = pt

quart (imperial)

qt imp = 1.1365225e-3 m^3
imperial quart = qt imp

quart (US dry)

qt US dry = 1.101220942715e-3 m^3
US dry quart = qt US dry

quart (US fluid)

qt = 946.352946e-6 m^3
qt US = qt
US qt = qt
US quart = qt
US fluid quart = qt
fluid quart = qt
quart = qt
quarts = qt

tablespoon (Canadian)

tbsp CA = 14.20653125e-6 m^3
Canadian tablepoon = tbsp CA
CA tablespoon = tbsp CA
CA tbsp = tbsp CA

tablespoon (imperial)

tbsp imp = 17.7581640625e-6 m^3
imperial tablespoon = tbsp imp
imperial tbsp = tbsp imp

tablespoon (US customary)

tbsp = 14.7867647825e-6 m^3
tbsp US = tbsp
tablepoon = tbsp
tablespoons = tbsp
US tablespoon = tbsp
US tbsp = tbsp

teaspoon (Canadian)

tsp CA = 4.73551041666666666666666e-6 m^3
Canadian teaspoon = tsp CA
CA teaspoon = tsp CA
CA tsp = tsp CA

teaspoon (imperial)

tsp imp = 5.9193880208333333333333333e-6 m^3
imperial teaspoon = tsp imp
imperial tsp = tsp imp

teaspoon (metric)

tsp metric = 5.0e-6 m^3
metric teaspoon = tsp metric
metric tsp = tsp metric

teaspoon (US customary)

tsp = 4.928921595e-6 m^3
tsp US = tsp
teaspoon = tsp
US teaspoon = tsp
US tsp = tsp

timber foot

timber foot = 0.028316846592 m^3

ton (displacement)

ton displacement = 0.99108963072 m^3

ton (freight)

ton freight = 1.13267386368 m^3

ton (water)

ton water = 1.01832416 m^3

Plane angle

rad = rad
radian = rad
radians = rad

arcminute; MOA

arcminute = 2pi/360/60 * rad
arc minute = arcminute
minute of arc = arcminute
arcmin = arcminute
amin = arcminute
MOA = arcminute
′ = arcminute

arcsecond

arcsecond = arcminute / 60
arc second = arcsecond
second of arc = arcsecond
arcsec = arcsecond
asec = arcsecond
″ = arcsecond

degree (of arc)

° = 2pi/360 * rad
deg = °
degree = °
degrees = °
degree of arc = °

grad; gradian; gon

grad = 2pi/400 * rad
gradian = grad
gon = grad

300gon in ° => 4.7124rad in °

octant

octant = 2pi/8 * rad

quadrant

quadrant = 2pi/4 * rad

turn

turn = 2pi * rad
turns = turn

Solid angle

steradian (SI unit)

sr = sr
steradian = sr

Mass

kg = kg
kilogram = kg
kilograms = kg

barge

barge = 20411.65665 kg

carat

ct = 205.196548333g/1000
carat = ct

dram (avoirdupois)

dr = 1.7718451953125g
dram = dr

grain

grain = 64.79891 g / 1000

gram

g = kg/1000
gram = g
grams = g

ounce (avoirdupois)

ounce = 28.349523125 g
ouces = ounce
oz = ounce

pound

lb = 0.45359237 kg
lbs = lb
pound = lb
pounds = lb

slug

slug = 14.593903 kg

stone

stone = 6.35029318 kg

ton, long

long ton = 1016.0469088 kg
long tn = long ton

ton, short

ton = 907.18474 kg
short ton = ton
sh tn = ton

Time

s = s
sec = s
secs = s
second = s
seconds = s

atomic unit of time

atomic unit of time = 2.418884254e-17 s
au time = atomic unit of time

century

century = 100 year

day

d = 86400 s
day = d
days = d

decade

decade = 10 year

fortnight

fortnight = 14 d

2fortnight in days = > 28d in days

hour

h = 3600 s
hour = h
hours = h

jiffy

jiffy = s/60

millennium

millennium = 1000 year

minute

min = 60 s
mins = min
minute = min
minutes = min

moment

moment = 90 s

month (full)

full month = 30 d

month (Greg. av.)

mo = year / 12
month = mo
months = mo

Planck time

Planck time = 5.3910632e-44 s
tP = Planck time

week

wk = 7d
week = wk
weeks = wk

year (Gregorian)

year = 31556952 s
y = year
yr = year
annum = year

Frequency

hertz (SI unit)

Hz = 1/s
cycles per second = Hz

revolutions per minute

rpm = (2pi * rad)/(60s)
RPM = rpm
revolutions per minute = rpm

Speed or velocity

knot

kn = 1852 m/(3600s)
kt = kn
knot = kn
NMPH = kn

mach number

mach = 295 m/s

Acceleration

galileo

galileo = 1e-2 m/s^2

standard gravity

standard gravity = 9.80665 m/s^2

Force

N = kg*m/s^2
newton = N
newtons = N

atomic unit of force

au force = 8.23872206e-8 N

dyne (cgs unit)

dyne = 1e-5 N
dyn = dyne

grave-force

kgf = 9.80665 N
grave force = kgf

kip; kip-force

kip = 4.4482216152605e3 N
kipf = kip
kip force = kip

ounce-force

ozf = 0.2780138509537812 N
ounce force = ozf

pound-force

lbf = 4.4482216152605 N
pound force = lbf

ton-force

tnf = 8.896443230521e3 N
ton force = tnf

Pressure or mechanical stress

Pa = N/m^2
pascal = Pa
Pascal = Pa

atmosphere (technical)

at = 9.80665e4 Pa
atmosphere technical = at

barye (cgs unit)

barye = 0.1 Pa

centimetre of mercury

cmHg = 1.33322e3 Pa
centimeter of mercury = cmHg
centimetre of mercury = cmHg

centimetre of water (4 °C)

cmH_2O = 98.0638 Pa
centimeter of water = cmH_20
centimetre of water = cmH_20
cmH20 = cmH_20

foot of mercury (conventional)

ftHg = 40.63666e3 Pa
foot of mercury = ftHg
feet of mercury = ftHg

foot of water (39.2 °F)

ftH_2O = 2.98898e3 Pa
ftH2O = ftH_2O
foot of water = ftH_2O
feet of water = ftH_2O

inch of mercury (conventional)

inHg = 3.386389e3 Pa
inch of mercury = inHg
inches of mercury = inHg

inch of water (39.2 °F)

inH_2O = 249.082 Pa
inch of water = inH_2O
inches of water = inH_2O

kip per square inch

ksi = 6.894757e6 Pa

pièze (mts unit)

pz = 1e3 Pa
pièze = pz

pound per square foot

psf = 47.88026 Pa

pound per square inch

psi = 6.894757e3 Pa

torr

torr = 101325/760 * Pa => 133.3224N/m^2

Torque or moment of force

Newton meter = N * m
Newton metre = Newton meter
newton meter = Newton meter
newton metre = Newton meter

foot-pound force

ft lbf = 1.3558179483314004 N*m

foot-poundal

ft pdl = 4.21401100938048e-2 N*m

metre kilogram

m kg = 0.101971621 N*m

Energy

J = N * m
Joule = J
joule = J
joules = J

barrel of oil equivalent

boe = 6.12e9 J
barrel of oil equivalent = bow

British thermal unit (International Table)

BTU = 1055.05585262 J
British thermal unit = BTU
british thermal unit = BTU

calorie (thermochemical)

cal = 4.184 J
calorie = cal
cals = cal
calories = cal

Celsius heat unit (International Table)

CHU = 1.899100534716e3 J

cubic centimetre of atmosphere; standard cubic centimetre

cc atm = 0.101325 J

cubic foot of atmosphere; standard cubic foot

cu ft atm = 2.8692044809344e3 J
cubic foot of atmosphere = cu ft atm
standard cubic foot = cu ft atm
scf = cu ft atm

cubic foot of natural gas

cubic foot of natural gas = 1.05505585262e6 J

cubic yard of atmosphere; standard cubic yard

cu yd atm = 77.4685209852288e3 J
cubic yard of atmosphere = cu yd atm
standard cubic yard = cu yd atm
scy = cu yd atm

electronvolt

eV = 1.60217733e-19 J
electronvolt = eV
electron volt = eV

erg (cgs unit)

erg = 1e-7 J

foot-pound force

ft lbf = 1.3558179483314004 J

foot-poundal

ft pdl = 4.21401100938048e-2 J

gallon-atmosphere (imperial)

imp gal atm = 460.63256925 J

gallon-atmosphere (US)

gal atm = 383.5568490138 J
US gal atm = gal atm

atomic unit of energy

E_h = 4.359744e-18 J
au energy = E_h

kilowatt-hour; Board of Trade Unit

kWh = 3.6e6 J
kilowatt hour = kWh
BOTU = kWh

atmosphere

l atm = 101.325 J
atmosphere = l atm    
sl = l atm

quad

quad = 1.05505585262e18 J

therm (US)

therm = 105.4804e6 J

thermie

th = 4.1868e6 J
thermie = th

ton of coal equivalent

ton of coal equivalent = 29.288e9 J
TCE = 29.288e9 J

ton of oil equivalent

TOE = 41.84e9 J

TNT

TNT = 4.184e9 J
tTNT = TNT

Power or heat flow rate

W = J / s
Watt = W
Watts = W
watt = W
watts = W

horsepower (boiler)

bhp = 9.810657e3 W
boiler horsepower = bhp    

horsepower (imperial mechanical)

hp = 745.69987158227022 W
horsepower = hp

lusec

lusec = 1.333e-4 W

poncelet

poncelet = 980.665 W
p = 980.665 W

square foot equivalent direct radiation

sq ft EDR = 70.337057 W

Action

atomic unit of action

au action = 1.05457168e-34 J*s

Dynamic viscosity

poise (cgs unit)

poise = 0.1 Pa*s

Electric current

A = A
Ampere = A
ampere = A
amp = A
amps = A

Electric charge

C = A * s
coulomb = C

atomic unit of charge

au charge = 1.602176462e-19 C

faraday

faraday = 96485.3383 C

milliampere hour

mAh = 3.6 C

Electric dipole

atomic unit of electric dipole moment

ea_0 = 8.47835281e-30 C*m
ea0 = ea_0

debye

debye = 3.33564095e-30 C*m

Electromotive force, electric potential difference

V = W / A
Volt = V
volt = V
Volts = V
volts = V

Electrical resistance

ohm (SI unit)

Ω = 1 V/A
Ohm = Ω
ohm = Ohm

Capacitance

F = (A * s) / V
farad = F

Magnetic flux

Wb = V*s
Weber = Wb
weber = Wb

maxwell (CGS unit)

Mx = 1e-8 Wb
Maxwell = Mx
maxwell = Mx

Magnetic flux density

T = Wb/m^2
Tesla = T
tesla = T

gauss (CGS unit)

gauss = 1e-4 T

Inductance

H = 1 Wb/A
Henry = H
henry = H

Temperature

K = K
Kelvin = K
kelvin = K

Information entropy

bit = bit
bits = bit

shannon

Sh = 9.56994016e-24 J/K

nibble

nibble = 4b

byte

B = 8bit
byte = B
bytes = B

kilobyte (kibibyte)

KB = 1024 B
KiB = KB

megabyte (mebibyte)

MiB = 1024KiB

gigabyte (gibibyte)

GiB = 1024MiB

terabyte (tebibyte)

TiB = 1024GiB

Luminous intensity

candela (SI base unit); candle

cd = cd
candela = cd
candle = cd

Luminance

footlambert

fL = 3.4262590996 cd/m^2
footlambert = fL

lambert

lambert = 3183.0988618 cd/m^2

Luminous flux

lm = cd * sr
lumen = lm

Illuminance

lx = lm / m^2
lux = lx

footcandle; lumen per square foot

fc = 10.763910417 lx
footcandle = fc

Radiation - source activity

Number of disintegrations per second.

Bq = 1/s
becquerel = Bq

curie

Ci = 3.7e10 Bq
curie = 3.7e10 Bq

rutherford (H)

rd = 1e6 Bq
rutherford = rd

Radiation - exposure

roentgen

R = 2.58e-4 C/kg
roentgen = R

Radiation - absorbed dose

Gy = J / kg
gray = Gy

rad

rad = 0.01 Gy

Radiation - equivalent dose

Sv = 1 J/kg
sievert = Sv

Röntgen equivalent man

rem = 0.01 Sv

The END