Temperature difference converter
Converts temperature differences, like ISA deviation: a change of 1 °C is 1 K and 1.8 °F.
18 °F is 10 K.
- Input
Provenance
- Computed by
- units.temperature-difference.convert 1.0.0, core 0.1.0
- Model
- Exact unit definitions
- Accuracy
- Exact to double precision: each conversion is one correctly rounded ratio of exact definitions
- Notes
- None
- Cites
- National Institute of Standards and Technology, Guide for the Use of the International System of Units (SI), NIST Special Publication 811
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Exact unit definitions
Accuracy: Exact to double precision: each conversion is one correctly rounded ratio of exact definitions
When to use this: Use this for a change in temperature rather than a temperature: an ISA deviation, a lapse rate's worth of cooling, the spread between dew point and air temperature, a tolerance band. A difference carries only the size of the scale's degree and none of its offset, so a change of one degree Celsius is a change of one kelvin and of 1.8 degrees Fahrenheit -- which is why it is a separate tool and not a setting on the other one.
Limitations: A difference has no zero and no absolute meaning: this will happily convert a negative one, because a temperature can fall, and it cannot tell you whether the number you gave it was a reading by mistake. That is the error worth guarding against, and only you can: put 10 °C through here and it stays 10 K, where as a temperature it would be 283.15 K. Kelvin and Celsius degrees are the same size, so those two directions change nothing at all.
Worked example: An ISA deviation of +18 °F in kelvins. Source: Exact unit definitions (NIST SP 811 Appendix B). It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.
You enter
- To unit
- K
- Value
- 18 °F
You get
- Converted
- 10 K
- Input
- 18 °F
Review: Not yet independently reviewed by a metrologist.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 22 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, National Institute of Standards and Technology, 2008 edition. Appendix B.8, Factors for units listed alphabetically.