. Author manuscript; available in PMC: 2017 May 31.

Published in final edited form as: J Integr Bioinform. 2015 Sep 4;12(2):266. doi: 10.2390/biecoll-jib-2015-266

Table 9.

Units recommended for use on different SBML model components. Note that avogadro is considered to be derived from dimensionless as a consequence of its definition; see Section 4.4.2.

Component attribute	Unit recommendations
Model `substanceUnits`	`mole`, `item`, `dimensionless`, `kilogram`, `gram`, or units derived from these
Model `timeUnits`	`second`, `dimensionless`, or units derived from these
Model `volumeUnits`	`litre`, `metre`³, `dimensionless`, or units derived from these
Model `areaUnits`	`metre`², `dimensionless`, or units derived from these
Model `lengthUnits`	`metre`, `dimensionless`, or units derived from these
Model `extentUnits`	`mole`, `item`, `dimensionless`, `kilogram`, `gram`, or units derived from these

Compartment `units`	Value of attribute `spatialDimensions`	Recommended units

	“ `3`“	`litre`, `metre`³, `dimensionless`, or units derived from these
	“ `2`“	`metre`², `dimensionless`, or units derived from these
	“ `1`“	`metre`, `dimensionless`, or units derived from these
	other	no specific recommendations

Species `substanceUnits`	`mole`, `item`, `dimensionless`, `kilogram`, `gram`, or units derived from these
Parameter `units`	no specific recommendations