Normalize a unit-tagged value
Reads any value with a unit, like “145 kts”, and returns it in canonical units (SI; degrees for angles).
A published result changed on 2026-09-23: Promoting these two tools to stable removed EXPERIMENTAL_TOOL from their warnings, which moved NOMINAL_VALUE_USED and UNIT_ASSUMED from index 1 to index 0 and broke the two vectors that pinned the index. Nothing computed changed. v001 is superseded by v021 and v002 by v025, both naming the warning by its code with the meta.warnings.*.code form the runner supports, so no warning sorting above them can shift them again -- the same fix geometry.validity.make-valid v001 took for the same reason. Changelog
145 kt is 74.594444 m/s in canonical units.
- Input
Provenance
- Computed by
- units.quantity.normalize 1.0.0, core 0.1.0
- Model
- Exact unit definitions
- Accuracy
- Exact to double precision
- 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
When to use this: Use this when you have a value written the way a document writes it -- 145 kts, 29.92 inHg, 15 C -- and want it in SI without first working out which converter it belongs to. It is the one to reach for from a script or an agent, where the unit is whatever the source happened to use.
Limitations: You have to say what the value measures: the same spelling means different things in different quantities, and the tool will not guess between them. A bare number with no unit is refused for the same reason. Angles come back in degrees rather than radians, which is a deliberate departure from strict SI -- a bearing is written in degrees everywhere it is used. And an ambiguous spelling the quantity does settle, like nm for a distance, is resolved with a warning rather than in silence.
Worked example: 145 kts in m/s. 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
- Quantity
- speed
- Value with unit
- 145 kts
You get
- Canonical value
- 74.594444 m/s
- Input
- 145 kt
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.
Changes
- 2026-09-23, result change: Promoting these two tools to stable removed EXPERIMENTAL_TOOL from their warnings, which moved NOMINAL_VALUE_USED and UNIT_ASSUMED from index 1 to index 0 and broke the two vectors that pinned the index. Nothing computed changed. v001 is superseded by v021 and v002 by v025, both naming the warning by its code with the meta.warnings.*.code form the runner supports, so no warning sorting above them can shift them again -- the same fix geometry.validity.make-valid v001 took for the same reason. Changelog
Checked against: 24 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.