Please read Introduction to CarbonKit before reading this so that you understand the concepts of profile items and profile item values.

Amounts returned by CarbonKit

Amounts returned by CarbonKit are usually in units of kilograms of carbon dioxide, but it is important to consult the documentation on a category to understand exactly what the returned value represents.

Profile item values

When setting a profile item value, it is important to specify your units explicitly. For example, to represent 100 kilometres travelled per month, you should set distance=100, distanceUnit=km and distancePerUnit=month. CarbonKit supports all units present in JScience.

Data item values

It is not usually necessary to be concerned with the units used in data items as CarbonKit handles unit conversion transparently with profile items, i.e. CarbonKit will ensure that the units specified by the user are converted to match those needed in the algorithm.

All values, units and perUnits are available for inspection via the API under /data. In most cases, to reduce the possibility of mistranslation, the units used in CarbonKit data items are the same as that in the specified source.

Supported Units

Many units are supported in CarbonKit. This list shows the common name for each unit we support, and in brackets, the name used when sending data to CarbonKit. As well as those listed below, many more obscure units are supported. See the JScience lists of SI and Non-SI units for the complete set.

In addition, the SI prefixes such as Mega (M), Micro (m), Kilo (k), and so on, are supported.

Note that unit names are case sensitive.


  • Grams (g)
  • Kilograms (kg)
  • Metric Tons / Tonnes (t)
  • Ounces (oz)
  • Pounds (lb)
  • Tons (UK imperial) (ton_uk)
  • Tons (US imperial) (ton_us)


  • Metres (m)
  • Kilometres (km)
  • Feet (ft)
  • Yards (yd)
  • Miles (mi)
  • Nautical Miles (nmi)


  • Litres (L)
  • Cubic Metres (m³)
  • Fluid Ounces (UK imperial) (oz_fl_uk)
  • Fluid Ounces (US imperial) (oz_fl)
  • Gallons (UK imperial) (gal_uk or gallon_uk)
  • Gallons (US imperial) (gal)


  • Kilowatt-Hours (kWh)
  • Joules (J)

Energy - BTU

  • 39 °F (BTU_ThirtyNineF)
  • Mean (BTU_Mean)
  • IT (BTU_IT)
  • 59 °F (BTU_FiftyNineF)
  • 60 °F (BTU_SixtyF)
  • 63 °F (BTU_SixtyThreeF)
  • Thermochemical (BTU_Thermochemical)
Note: These units are based on those defined here. See this page for more details on prefixes.

Energy - Therm

  • 39 °F (thm_ThirtyNineF)
  • Mean (thm_Mean)
  • IT (thm_IT)
  • EC (thm_ec, alias of thm_IT)
  • ISO (thm_ISO)
  • 59 °F (thm_FiftyNineF)
  • US (thm_us, alias of thm_FiftyNineF)
  • 60 °F (thm_SixtyF)
  • 63 °F (thm_SixtyThreeF)
  • Thermochemical (thm_Thermochemical)
Note: These units are based on the BTU units defined above and simply multiplied by 100,000.


  • Second (s)
  • Minute (min)
  • Hour (h)
  • Day (day)
  • Week (week)
  • Month (month)
  • Year (year)

This category has no data items
Log in to perform calculations on this data
Name: Units
Full path: /documentation/Units
Parent Category: Documentation