Units

The seven SI base units are m, kg, s, A, K, mol and cd. Every other built-in unit is defined from them, below. A unit is a value like any other, so kip := 1000 lbf in a sheet adds one, and a definition of the same name as a unit replaces it in that sheet.

Length

Unit	Defined as
mm	0.001 m
cm	0.01 m
km	1000 m
μm	1e-6 m
in	0.0254 m
ft	12 in
yd	3 ft
mi	5280 ft

Time and frequency

Unit	Defined as
ms	0.001 s
min	60 s
sec	s
hr	60 min
h	hr
mph	mi/hr
kph	km/hr
day	24 hr
week	7 day
yr	365.2422 day
Hz	1/s
kHz	1000 Hz
MHz	1e6 Hz

Angle

Angles are dimensionless, unless a sheet makes them a dimension (angle: dimension), when rad is its unit.

Unit	Defined as
rad	1
deg	π/180
rev	2*π
gon	π/200

Ratios

% is a hundredth: ξ := 5 %. It is written in backticks in the text, since % can’t start a plain name.

Unit	Defined as
`%`	0.01

Mass

g is gravity (below); the gram is the upright \rm g, drawn upright like every unit. mg is the milligram.

Unit	Defined as
\rm g	0.001 kg
mg	0.000001 kg
t	1000 kg
tonne	t
lb	0.45359237 kg
ton	2000 lb

Temperature

°C and °F are points on a scale: 20 °C is 293.15 K, and = ? °C shows a temperature on the scale. Here they are one degree; each scale’s zero is built in. A temperature difference is Δ°C or Δ°F, and R is the rankine.

Unit	Defined as
°C	K
°F	5/9*K
Δ°C	K
Δ°F	5/9*K
R	5/9*K

Acceleration

Unit	Defined as
g	9.80665 m/s^2

Force

Unit	Defined as
N	kg*m/s^2
kN	1000 N
MN	1e6 N
GN	1e9 N
kgf	kg*g
tonnef	tonne*g
lbf	lb*g
kip	1000 lbf

Pressure and stress

Unit	Defined as
Pa	N/m^2
kPa	1000 Pa
MPa	1e6 Pa
GPa	1e9 Pa
bar	1e5 Pa
atm	101325 Pa
psi	lbf/in^2
ksi	1000 psi

Energy and power

Unit	Defined as
J	N*m
joule	J
kJ	1000 J
MJ	1e6 J
GJ	1e9 J
W	J/s
kW	1000 W
MW	1e6 W
GW	1e9 W
BTU	1055.05585262 J
hp	550 ft*lbf/s

Volume

Unit	Defined as
L	0.001 m^3
mL	0.001 L
gal	3.785411784 L

Electrical

Unit	Defined as
mA	0.001 A
C	A*s
V	W/A
volt	V
kV	1000 V
Ω	V/A
ohm	Ω
S	1/Ω
F	C/V
Wb	V*s
T	Wb/m^2
H	Wb/A
mH	0.001*H

Light, radiation, chemistry

Unit	Defined as
lm	cd
lx	lm/m^2
Bq	1/s
Gy	J/kg
Sv	J/kg
kat	mol/s