---
title: Units and Measurement
framework: foundation
role: collectionGroup
role_heading: API Collection
path: foundation/units-and-measurement
---

# Units and Measurement

Label numeric quantities with physical dimensions to allow locale-aware formatting and conversion between related units.

## Topics

### Essentials

- [Measurement](foundation/measurement.md)
- [NSMeasurement](foundation/nsmeasurement.md)
- [Unit](foundation/unit.md)
- [Dimension](foundation/dimension.md)

### Conversion

- [UnitConverter](foundation/unitconverter.md)
- [UnitConverterLinear](foundation/unitconverterlinear.md)

### Physical Dimension

- [UnitArea](foundation/unitarea.md)
- [UnitLength](foundation/unitlength.md)
- [UnitVolume](foundation/unitvolume.md)
- [UnitAngle](foundation/unitangle.md)

### Mass, Weight, and Force

- [UnitMass](foundation/unitmass.md)
- [UnitPressure](foundation/unitpressure.md)

### Time and Motion

- [UnitAcceleration](foundation/unitacceleration.md)
- [UnitDuration](foundation/unitduration.md)
- [UnitFrequency](foundation/unitfrequency.md)
- [UnitSpeed](foundation/unitspeed.md)

### Energy, Heat, and Light

- [UnitEnergy](foundation/unitenergy.md)
- [UnitPower](foundation/unitpower.md)
- [UnitTemperature](foundation/unittemperature.md)
- [UnitIlluminance](foundation/unitilluminance.md)

### Electricity

- [UnitElectricCharge](foundation/unitelectriccharge.md)
- [UnitElectricCurrent](foundation/unitelectriccurrent.md)
- [UnitElectricPotentialDifference](foundation/unitelectricpotentialdifference.md)
- [UnitElectricResistance](foundation/unitelectricresistance.md)

### Concentration and Dispersion

- [UnitConcentrationMass](foundation/unitconcentrationmass.md)
- [UnitDispersion](foundation/unitdispersion.md)

### Fuel Efficiency

- [UnitFuelEfficiency](foundation/unitfuelefficiency.md)

### Data Storage

- [UnitInformationStorage](foundation/unitinformationstorage.md)

### Formatting Measurements

- [MeasurementFormatUnitUsage](foundation/measurementformatunitusage.md)

## See Also

### Fundamentals

- [Numbers, Data, and Basic Values](foundation/numbers-data-and-basic-values.md)
- [Strings and Text](foundation/strings-and-text.md)
- [Collections](foundation/collections.md)
- [Dates and Times](foundation/dates-and-times.md)
- [Data Formatting](foundation/data-formatting.md)
- [Filters and Sorting](foundation/filters-and-sorting.md)