SI units and prefixes (BIPM SI Reference Point)

The 7 SI base units, 22 named SI derived units, and 24 SI prefixes from the BIPM SI Reference Point (the authoritative digital reference of the SI Digital Framework, CC BY 3.0 IGO). One document per unit or prefix: base units carry the current definition with its defining constant and superseded definitions, derived units the expression in base and other SI units, and prefixes the exponent and scaling factor.

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Documents

Showing 25–48 of 53 documents

Document	Version
mega (M) mega (symbol M) is the SI prefix for a factor of 10⁶ (scaling factor 1000000), per the BIPM SI Reference Point.	v1
metre (m) The metre (symbol m) is the SI base unit of length, per the BIPM SI Reference Point.	v1
micro (μ) micro (symbol μ) is the SI prefix for a factor of 10⁻⁶ (scaling factor 0.000001), per the BIPM SI Reference Point.	v1
milli (m) milli (symbol m) is the SI prefix for a factor of 10⁻³ (scaling factor 0.001), per the BIPM SI Reference Point.	v1
mole (mol) The mole (symbol mol) is the SI base unit of amount of substance, per the BIPM SI Reference Point.	v1
nano (n) nano (symbol n) is the SI prefix for a factor of 10⁻⁹ (scaling factor 0.000000001), per the BIPM SI Reference Point.	v1
newton (N) The newton (symbol N) is a named SI derived unit of force, per the BIPM SI Reference Point.	v1
ohm (Ω) The ohm (symbol Ω) is a named SI derived unit of electric resistance, per the BIPM SI Reference Point.	v1
pascal (Pa) The pascal (symbol Pa) is a named SI derived unit of pressure, per the BIPM SI Reference Point.	v1
peta (P) peta (symbol P) is the SI prefix for a factor of 10¹⁵ (scaling factor 1000000000000000), per the BIPM SI Reference Point.	v1
pico (p) pico (symbol p) is the SI prefix for a factor of 10⁻¹² (scaling factor 0.000000000001), per the BIPM SI Reference Point.	v1
quecto (q) quecto (symbol q) is the SI prefix for a factor of 10⁻³⁰ (scaling factor 0.000000000000000000000000000001), per the BIPM SI Reference Point.	v1
quetta (Q) quetta (symbol Q) is the SI prefix for a factor of 10³⁰ (scaling factor 1000000000000000000000000000000), per the BIPM SI Reference Point.	v1
radian (rad) The radian (symbol rad) is a named SI derived unit of plane angle, per the BIPM SI Reference Point.	v1
ronna (R) ronna (symbol R) is the SI prefix for a factor of 10²⁷ (scaling factor 1000000000000000000000000000), per the BIPM SI Reference Point.	v1
ronto (r) ronto (symbol r) is the SI prefix for a factor of 10⁻²⁷ (scaling factor 0.000000000000000000000000001), per the BIPM SI Reference Point.	v1
second (s) The second (symbol s) is the SI base unit of time, per the BIPM SI Reference Point.	v1
siemens (S) The siemens (symbol S) is a named SI derived unit of electric conductance, per the BIPM SI Reference Point.	v1
sievert (Sv) The sievert (symbol Sv) is a named SI derived unit of dose equivalent, per the BIPM SI Reference Point.	v1
steradian (sr) The steradian (symbol sr) is a named SI derived unit of solid angle, per the BIPM SI Reference Point.	v1
tera (T) tera (symbol T) is the SI prefix for a factor of 10¹² (scaling factor 1000000000000), per the BIPM SI Reference Point.	v1
tesla (T) The tesla (symbol T) is a named SI derived unit of magnetic flux density, per the BIPM SI Reference Point.	v1
volt (V) The volt (symbol V) is a named SI derived unit of electric potential difference, per the BIPM SI Reference Point.	v1
watt (W) The watt (symbol W) is a named SI derived unit of power, per the BIPM SI Reference Point.	v1

Source, review, and usage

Published on Koskamo by: Koskamo
Version: 54
Documents: 53 documents
Reviewed: 2026-10-05
Last approved change: 2026-10-05
Agent lookups: 0 in the last 90 days
Reuse: BIPM SI Reference Point (si-digital-framework.org), the SI defining constants, base and derived units, and prefixes; CC BY 3.0 IGO
Review status: Published by Koskamo; proposed revisions require Koskamo approval

Original sources are linked on each document. Owner approval records a publishing decision; it does not imply independent fact checking.

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Change history

Every change that reached this dataset. Proposals from contributors land only after Koskamo approves them.

Published by Koskamo2026-10-05
quecto (q) · v1
Published by Koskamo2026-10-05
ronto (r) · v1
Published by Koskamo2026-10-05
yocto (y) · v1
Published by Koskamo2026-10-05
zepto (z) · v1
Published by Koskamo2026-10-05
atto (a) · v1
Published by Koskamo2026-10-05
femto (f) · v1
Published by Koskamo2026-10-05
pico (p) · v1
Published by Koskamo2026-10-05
nano (n) · v1
Published by Koskamo2026-10-05
micro (μ) · v1
Published by Koskamo2026-10-05
milli (m) · v1