The catalog of built-in units, grouped by dimension — 49 dimensions, 288 named units (before metric prefixes). Generated from the headers by docs/reference/gen_reference.py; do not edit by hand.

Each unit is available as a type (meters, meters<double>) and, where shown, a literal (5.0_m). Units marked yes under Prefixes also provide every SI metric prefix from femto to peta (e.g. kilometers/_km, millimeters/_mm). Include the umbrella header <units.h> for all of them, or a single <units/DIMENSION.h> for one dimension.

For units shared across dimensions (e.g. pounds of mass vs. force), qualify with the dimension namespace: units::mass::pounds vs units::force::pounds.

acceleration

Unit	Literal	Prefixes
meters_per_second_squared	_mps2
feet_per_second_squared	_fps2
standard_gravity	_SG
gals	_Gal

angle

Unit	Literal	Prefixes
radians	_rad	yes
degrees	_deg
arcminutes	_arcmin
arcseconds	_arcsec
milliarcseconds	_mas
turns	_tr
gradians	_gon
angular_mils	_amil
compass_points	_cpt

angular velocity

Unit	Literal	Prefixes
radians_per_second	_rad_per_s
degrees_per_second	_deg_per_s
revolutions_per_minute	_rpm
revolutions_per_second	_rps
milliarcseconds_per_year	_mas_per_yr

area

Unit	Literal	Prefixes
square_meters	_m2
square_feet	_ft2
square_inches	_in2
square_miles	_mi2
square_kilometers	_km2
hectares	_ha
acres	_acre
roods	_rood
square_rods	_rd2

capacitance

Unit	Literal	Prefixes
farads	_F	yes

charge

Unit	Literal	Prefixes
coulombs	_C	yes
ampere_hours	_Ah	yes
abcoulombs	_abC
statcoulombs	_statC

concentration

Unit	Literal	Prefixes
parts_per_million	_ppm
parts_per_billion	_ppb
parts_per_trillion	_ppt
percent	_pct

conductance

Unit	Literal	Prefixes
siemens	_S	yes

current

Unit	Literal	Prefixes
amperes	_A	yes
abamperes	_abA
statamperes	_statA

data

Unit	Literal	Prefixes
bytes	_B
kilobytes	_kB
megabytes	_MB
gigabytes	_GB
terabytes	_TB
petabytes	_PB
exabytes	_EB
kibibytes	_KiB
mebibytes	_MiB
gibibytes	_GiB
tebibytes	_TiB
pebibytes	_PiB
exbibytes	_EiB
bits	_b
kilobits	_kb
megabits	_Mb
gigabits	_Gb
terabits	_Tb
petabits	_Pb
exabits	_Eb
kibibits	_Kib
mebibits	_Mib
gibibits	_Gib
tebibits	_Tib
pebibits	_Pib
exbibits	_Eib
nibbles	_nibble

data transfer rate

Unit	Literal	Prefixes
bytes_per_second	_Bps
exabytes_per_second	_EBps
bits_per_second	_bps
exabits_per_second	_Ebps

density

Unit	Literal	Prefixes
kilograms_per_cubic_meter	_kg_per_m3
grams_per_milliliter	_g_per_mL
kilograms_per_liter	_kg_per_L
ounces_per_cubic_foot	_oz_per_ft3
ounces_per_cubic_inch	_oz_per_in3
ounces_per_gallon	_oz_per_gal
pounds_per_cubic_foot	_lb_per_ft3
pounds_per_cubic_inch	_lb_per_in3
pounds_per_gallon	_lb_per_gal
slugs_per_cubic_foot	_slug_per_ft3

energy

Unit	Literal	Prefixes
joules	_J	yes
calories	_cal	yes
kilowatt_hours	_kWh
watt_hours	_Wh
british_thermal_units	_BTU
british_thermal_units_iso	_BTU_iso
british_thermal_units_59	_BTU59
therms	_thm
foot_pounds	_ftlbf
ergs	_erg
calories_it	_cal_it
tons_of_tnt	_tTNT

energy density

Unit	Literal	Prefixes
joules_per_meter_cubed	_J_per_m3	yes

force

Unit	Literal	Prefixes
newtons	_N	yes
pounds	_lbf
dynes	_dyn
kiloponds	_kp
poundals	_pdl
kips	_kip
ounces_force	_ozf
grams_force	_gf
short_tons_force	_tonf
long_tons_force	_ltonf
sthenes	_sn

frequency

Unit	Literal	Prefixes
hertz	_Hz	yes

illuminance

Unit	Literal	Prefixes
lux	_lx	yes
footcandles	_fc
lumens_per_square_inch	_lm_per_in2
phots	_ph

impedance

Unit	Literal	Prefixes
ohms	_Ohm	yes

inductance

Unit	Literal	Prefixes
henries	_H	yes

irradiance

Unit	Literal	Prefixes
watts_per_meter_squared	_W_per_m2	yes

jerk

Unit	Literal	Prefixes
meters_per_second_cubed	_mps3	yes
feet_per_second_cubed	_fps3

length

Unit	Literal	Prefixes
meters	_m	yes
feet	_ft
inches	_in
mils	_mil
miles	_mi
nautical_miles	_nmi
astronomical_units	_au
lightyears	_ly
parsecs	_pc
angstroms	_angstrom
cubits	_cbt
fathoms	_ftm
chains	_ch
furlongs	_fur
hands	_hand
leagues	_lea
nautical_leagues	_nl
yards	_yd
rods	_rod
links	_li
barleycorns	_bc
nails	_nail
spans	_span
picas	_pica
points	_pnt

luminance

Unit	Literal	Prefixes
candelas_per_square_meter	_cd_per_m2	yes
stilbs	_sb
apostilbs	_asb
brils	_bril
skots	_sk
lamberts	_la
millilamberts	_mla
foot_lamberts	_ftL

luminous flux

Unit	Literal	Prefixes
lumens	_lm	yes

luminous intensity

Unit	Literal	Prefixes
candelas	_cd	yes

magnetic field strength

Unit	Literal	Prefixes
teslas	_Te	yes
gauss	_G

magnetic flux

Unit	Literal	Prefixes
webers	_Wb	yes
maxwells	_Mx

mass

Unit	Literal	Prefixes
grams	_g	yes
tonnes	_t
pounds	_lb
long_tons	_ln_conversion_factor
short_tons	_sh_conversion_factor
stone	_st
ounces	_oz
carats	_ct
slugs	_slug
grains	_gr
avoirdupois_drams	_dr_av
pennyweights	_dwt
troy_ounces	_ozt
troy_pounds	_lbt
hundredweights	_cwt
short_hundredweights	_sh_cwt

power

Unit	Literal	Prefixes
watts	_W	yes
horsepower	_hp
metric_horsepower	_hpM
electrical_horsepower	_hpE
tons_of_refrigeration	_TR

pressure

Unit	Literal	Prefixes
pascals	_Pa	yes
bars	_bar
millibars	_mbar
atmospheres	_atm
pounds_per_square_inch	_psi
torrs	_torr
millimeters_of_mercury	_mmHg
inches_of_mercury	_inHg
technical_atmospheres	_at
pounds_per_square_foot	_psf
kips_per_square_inch	_ksi
baryes	_Ba
piezes	_pz
centimeters_of_water	_cmH2O
millimeters_of_water	_mmH2O
inches_of_water	_inH2O

radiance

Unit	Literal	Prefixes
watts_per_steradian_per_meter_squared	_W_per_srm2	yes

radiant intensity

Unit	Literal	Prefixes
watts_per_steradian	_W_per_sr	yes

radiation

Unit	Literal	Prefixes
becquerels	_Bq	yes
grays	_Gy	yes
sieverts	_Sv	yes
curies	_Ci
rutherfords	_rd
radiation_absorbed_dose	_rads
roentgens_equivalent_man	_rem

solid angle

Unit	Literal	Prefixes
steradians	_sr	yes
degrees_squared	_deg2
spats	_sp

spectral flux

Unit	Literal	Prefixes
watts_per_meter	_W_per_m	yes

spectral intensity

Unit	Literal	Prefixes
watts_per_steradian_per_meter	_W_per_srm	yes

spectral irradiance

Unit	Literal	Prefixes
watts_per_meter_cubed	_W_per_m3	yes

spectral radiance

Unit	Literal	Prefixes
watts_per_steradian_per_meter_cubed	_W_per_srm3	yes

substance

Unit	Literal	Prefixes
mols	_mol	yes
pound_moles	_lbmol

substance concentration

Unit	Literal	Prefixes
molars	_M	yes

substance mass

Unit	Literal	Prefixes
grams_per_mole	_g_per_mol	yes

temperature

Unit	Literal	Prefixes
kelvin	_K
celsius	_degC
fahrenheit	_degF
reaumur	_Re
rankine	_Ra

time

Unit	Literal	Prefixes
seconds	_s	yes
minutes	_min
hours	_hr
days	_d
weeks	_wk
years	_yr
julian_years	_a_j
gregorian_years	_a_g
fortnights	_fn
decades	_dec
centuries	_cent
millennia	_kyr

torque

Unit	Literal	Prefixes
newton_meters	_Nm
pound_feet	_lbf_ft
foot_poundals	_ftpdl
inch_pounds	_inlb
meter_kilograms	_mkgf

velocity

Unit	Literal	Prefixes
meters_per_second	_mps
feet_per_second	_fps
miles_per_hour	_mph
kilometers_per_hour	_kph
knots	_kts
feet_per_minute	_fpm
meters_per_minute	_mpm
inches_per_second	_ips
kilometers_per_second	_kmps

viscosity

Unit	Literal	Prefixes
pascal_seconds	_Pa_s
poise	_P
centipoise	_cP
square_meters_per_second	_m2_per_s
stokes	_St
centistokes	_cSt

voltage

Unit	Literal	Prefixes
volts	_V	yes
statvolts	_statV
abvolts	_abV

volume

Unit	Literal	Prefixes
cubic_meters	_m3
cubic_millimeters	_mm3
cubic_kilometers	_km3
liters	_L	yes
cubic_inches	_in3
cubic_feet	_ft3
cubic_yards	_yd3
cubic_miles	_mi3
gallons	_gal
quarts	_qt
pints	_pt
cups	_c
fluid_ounces	_fl_oz
barrels	_bl
bushels	_bu
cords	_cord
cubic_fathoms	_fm3
tablespoons	_tbsp
teaspoons	_tsp
pinches	_pinch
dashes	_dash
drops	_drop
fifths	_fifth
drams	_dr
gills	_gi
pecks	_pk
sacks	_sck
shots	_shts
strikes	_strk

volume flow rate

Unit	Literal	Prefixes
cubic_meters_per_second	_m3_per_s
cubic_meters_per_hour	_m3_per_hr
liters_per_second	_L_per_s
liters_per_minute	_L_per_min
gallons_per_minute	_gpm
gallons_per_hour	_gph
cubic_feet_per_second	_cfs
cubic_feet_per_minute	_cfm