ISO 80000-3: Quantities and Units of Space and Time
ISO 80000-3 expands the International System of Quantities into the practical language of geometry, navigation, and motion. It codifies how we report distance, duration, and speed so scientific data, transportation networks, and manufacturing systems exchange information without conversion errors. Pair this deep dive with the ISO 80000 overview and the part-by-part quick tables for fast cross-referencing.
Before implementing Part 3, make sure your terminology aligns with ISO 80000-1 and the typography rules laid out in ISO 80000-2. These volumes ensure that symbols like Δt, ω, and θ retain consistent meaning across design documents and analytics dashboards.
New to measurement science? Start with our unit of measurement primer and the SI spotlight to see how ISO terminology connects to globally agreed constants. When you are ready to apply the rules, launch the meters to feet converter or minutes to hours calculator to reinforce coherent units with practical exercises.
Scope of ISO 80000-3
Part 3 groups quantities that describe how matter occupies space and evolves with time. From basic distance measurement to the angular velocity of rotating equipment, every definition builds on the coherent metre-second structure established in the SI. Use the highlights below to map the domains you need to support.
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Geometric extent
Defines how to express one-, two-, and three-dimensional measures such as length, area, and volume with coherent SI units.
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Temporal scales
Clarifies how duration, period, and frequency build on the second while accepting minute and hour for applied timing.
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Kinematics
Introduces velocity, acceleration, and angular motion quantities that connect spatial change to elapsed time.
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Angular measurement
Specifies plane and solid angles, covering radians, degrees, and steradians so navigation, astronomy, and graphics stay interoperable.
Primary quantities and coherent units
ISO 80000-3 keeps the metre (m) and second (s) at the core while extending them to cover derived spatial and temporal measures. It also recognises commonly used non-SI units such as the degree and litre, provided that documentation maintains clear conversions. Use this table as a reference when drafting specifications or validating calculator logic.
| Quantity | Symbol | Coherent unit |
|---|---|---|
| Length | l | metre (m) |
| Area | A | square metre (m²) |
| Volume | V | cubic metre (m³) |
| Time | t | second (s) |
| Time interval | Δt | second (s), minute (min), hour (h) |
| Frequency | f, ν | hertz (Hz = 1/s) |
| Period | T | second (s) |
| Angular velocity | ω | radian per second (rad/s) |
| Speed | v | metre per second (m/s) |
| Acceleration | a | metre per second squared (m/s²) |
| Plane angle | θ | radian (rad), degree (°) |
| Solid angle | Ω | steradian (sr) |
Need quick conversions while working with these quantities? Bookmark the hectares to acres converter for land surveys, the MPH to KPH converter for fleet dashboards, and the minutes to hours tool for shift planning.
Understanding derived relationships
The strength of ISO 80000-3 lies in how it links spatial and temporal quantities. Radial and linear motion, cycles and periods, or dwell times and throughput all tie back to SI base units. The following insights highlight relationships to document in technical manuals, API schemas, or educational material.
Radian-based coherence
Radians keep calculus-friendly relationships between arc length, angular velocity, and harmonic motion. Degrees remain acceptable for communication, but ISO 80000-3 encourages radian-first for derived equations.
Frequency and time
Hertz equals one cycle per second. Part 3 ties f = 1/T so that oscillators, rotating machinery, and digital clocks exchange values without conversion errors.
Linear versus rotational motion
Angular quantities share the same dimensionless nature as the radian, letting engineers move between tangential speed (v = r·ω) and translational speed seamlessly.
Documenting these links prevents spreadsheet macros or analytics pipelines from mixing incompatible units. When teaching the material, pair Part 3 with the ISO 80000-2 notation guide to reinforce derivative and vector notation.
Implementation roadmap
Bringing ISO 80000-3 into production environments is a mix of data governance and training. Use these steps as a starting checklist, then embed cross-links to calculators for hands-on validation.
- Catalogue spatial data
List every place your organisation stores coordinates, areas, or volumes—from CAD drawings to logistics manifests. Flag non-SI units (square feet, gallons) so you can map them to coherent metre-based forms.
- Audit timing conventions
Check whether scheduling systems mix seconds, minutes, and hours. ISO 80000-3 allows minute and hour for everyday timing, but document conversions back to the second for analytics.
- Validate speed and frequency inputs
Set up calculators or scripts that enforce SI units for velocity, acceleration, and angular rates before data moves into simulations or dashboards.
As you standardise units, schedule refresher sessions that compare ISO terminology with locally used shortcuts. Encourage teams to test calculations using tools like the meters to feet converter and the MPH to KPH calculator to spot discrepancies early.
Further reading and tools
Keep building your reference library with the articles and calculators below. They connect ISO 80000-3 to broader metrology guidance and day-to-day problem solving.
Articles
- Time: Definition, Units, Realization, and Use Connect Part 3 guidance with a full overview of time scales, metrology, and cross-domain applications.
- ISO 80000 overview Review how the 13 parts fit together and where Part 3 sits within the mechanics cluster.
- ISO 80000-1 general principles Connect Part 3's quantities back to the International System of Quantities definitions and typography rules.
- International System of Units (SI) Refresh the SI base and derived unit definitions that underpin the metre-second relationships.
- What is a unit of measurement? Share this primer with newcomers before diving into the geometric and temporal vocabulary of Part 3.
Calculators
- Meters to feet converter Practice translating linear dimensions from customary units into the metre-based SI framework.
- Minutes to hours converter Check timing conversions when schedules or logs mix minute and hour conventions with ISO-compliant seconds.
- MPH to KPH converter Reinforce how speed values trace back to metre-per-second coherence even when presented in everyday units.
- Hectares to acres converter Bridge land area reporting between SI-friendly square metres and legacy imperial measures.
Ready for the next disciplines after space and time? Continue with the mechanics chapter (Part 4) or explore how thermodynamics builds on these foundations in ISO 80000-5.