Name

Symbol 

Value in SI units

minute (time)

min

1 min = 60 s

hour

h

1 h = 60 min = 3600 s

day

d

1 d = 24 h = 86 400 s

degree (angle)

°

1° = ( /180) rad

minute (angle)

1 = (1/60)° = ( /10 800) rad

second (angle)

1 = (1/60) = ( /648 000) rad

liter

L

1 L = 1 dm³ = 10^-3 m³

metric ton

t

1 t = 10³ kg

neper

Np

1 Np = 1

bel

B

1 B = (1/2) ln 10 Np ^(a)

electronvolt

eV

1 eV = 1.602 18 x 10^-19 J, approximately

unified atomic mass unit

u

1 u = 1.660 54 x 10^-27 kg, approximately

astronomical unit

ua

1 ua = 1.495 98 x 10¹¹ m, approximately

nautical mile ^(z)

1 nautical mile = 1852 m

knot ^(z)

1 nautical mile per hour = (1852/3600) m/s

are ^(z)

a

1 a = 1 dam² = 10² m²

hectare ^(z) 

ha

1 ha = 1 hm² = 10⁴ m²

bar ^(z)

bar

1 bar = 0.1 MPa = 100 kPa = 1000 hPa = 10⁵ Pa

ångström ^(z)

Å

1 Å = 0.1 nm = 10^-10 m

barn ^(z)

b

1 b = 100 fm² = 10^-28 m²

curie ^(z)

Ci

1 Ci = 3.7 x 10¹⁰ Bq

roentgen ^(z)

R

1 R = 2.58 x 10^-4 C/kg

rad ^(z)

rad

1 rad = 1 cGy = 10^-2 Gy

rem ^(z)

rem

1 rem = 1 cSv = 10^-2 Sv

^(a) Although the neper is coherent with SI units and is accepted by the CIPM, it has not been adopted by the General Conference on Weights and Measures (CGPM, Conférence Générale des Poids et Mesures) and is thus not an SI unit.
^(z) Other units outside the SI that are currently accepted for use with the SI by NIST which are subject to future review