mittakertoimien

Mittakertoimet, or conversion factors, are numerical multipliers used to translate quantities from one unit to another. They express how many units of a given measure correspond to a unit in another system, so a value in a source unit can be re-expressed in a target unit by multiplication. In practice, a conversion factor is derived from an equality between units and can be applied in both directions depending on the desired outcome.

Common examples include length, volume, time and mass conversions. For instance, 1 inch equals 2.54 centimeters, which provides a factor for converting between inches and centimeters. Similarly, 1 meter equals 100 centimeters, 1 liter equals 1000 cubic centimeters, 1 hour equals 60 minutes, and 1 minute equals 60 seconds. These factors are often exact by definition (such as 1 inch = exactly 2.54 cm) or determined by standardization.

Not all unit changes are purely multiplicative. Temperature conversions between Celsius, Fahrenheit and Kelvin involve additive offsets in addition to any multiplicative scaling, so they are better described by conversion formulas rather than a single multiplicative factor.

Mittakertoimet are widely used in science, engineering and everyday calculations to perform dimensional analysis, ensure consistency of units in equations, and propagate measurement uncertainty through calculations. They underlie most data reporting and computational workflows by providing a straightforward bridge between different unit systems. See also dimensional analysis, SI units, and unit conversion.