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Length converters

Length is the simplest physical quantity to convert: every unit on this page is exactly a ratio of the SI meter. The 1959 international yard and pound agreement fixed inches at 25.4 mm exactly. The unit definitions are exact; displayed factors are rounded for readability, and calculations use IEEE 754 double-precision arithmetic.

Popular length conversions

Millimeters to Centimeters
mm → cm
Millimeters to Meters
mm → m
Millimeters to Kilometers
mm → km
Millimeters to Inches
mm → in
Millimeters to Feet
mm → ft
Millimeters to Yards
mm → yd
Millimeters to Miles
mm → mi
Centimeters to Millimeters
cm → mm
Centimeters to Meters
cm → m
Centimeters to Kilometers
cm → km
Centimeters to Inches
cm → in
Centimeters to Feet
cm → ft
Centimeters to Yards
cm → yd
Centimeters to Miles
cm → mi
Meters to Millimeters
m → mm
Meters to Centimeters
m → cm
Meters to Kilometers
m → km
Meters to Inches
m → in
Meters to Feet
m → ft
Meters to Yards
m → yd
Meters to Miles
m → mi
Kilometers to Millimeters
km → mm
Kilometers to Centimeters
km → cm
Kilometers to Meters
km → m
Kilometers to Inches
km → in
Kilometers to Feet
km → ft
Kilometers to Yards
km → yd
Kilometers to Miles
km → mi
Inches to Millimeters
in → mm
Inches to Centimeters
in → cm
Inches to Meters
in → m
Inches to Kilometers
in → km
Inches to Feet
in → ft
Inches to Yards
in → yd
Inches to Miles
in → mi
Feet to Millimeters
ft → mm
Feet to Centimeters
ft → cm
Feet to Meters
ft → m
Feet to Kilometers
ft → km
Feet to Inches
ft → in
Feet to Yards
ft → yd
Feet to Miles
ft → mi
Yards to Millimeters
yd → mm
Yards to Centimeters
yd → cm
Yards to Meters
yd → m
Yards to Kilometers
yd → km
Yards to Inches
yd → in
Yards to Feet
yd → ft
Yards to Miles
yd → mi
Miles to Millimeters
mi → mm
Miles to Centimeters
mi → cm
Miles to Meters
mi → m
Miles to Kilometers
mi → km
Miles to Inches
mi → in
Miles to Feet
mi → ft
Miles to Yards
mi → yd
Micrometers to Millimeters
µm → mm
Millimeters to Micrometers
mm → µm
Nanometers to Micrometers
nm → µm
Micrometers to Nanometers
µm → nm
Nanometers to Meters
nm → m
Meters to Nanometers
m → nm

Related tools

Height converter
Feet + inches ↔ centimetres

All length units

The 14 units below can be selected as source or target inside any length converter.

Length units in terms of the meter

Every length unit on Convertitive is defined as an exact ratio of the meter (m), the reference unit for this category. The table below shows what one of each unit equals in meters — the constant every converter on this page is built from.

Length units expressed in meters
UnitSymbol1 unit in meters
Millimetersmm0.001 m
Centimeterscm0.01 m
Metersmbase unit
Kilometerskm1000 m
Inchesin0.0254 m
Feetft0.3048 m
Yardsyd0.9144 m
Milesmi1609.34 m
Micrometersµm1.0000 × 10^−6 m
Nanometersnm1.0000 × 10^−9 m
Nautical milesnmi1852 m
Light yearsly9.4607 × 10^15 m
Parsecspc3.0857 × 10^16 m
AngstromsÅ1.0000 × 10^−10 m

To convert between any two units, Convertitive scales the input to meters using these factors and then back out to the target unit — so every result on this page traces to a single, exact definition rather than a chained approximation. Pick any pair above to see the formula, a 50-row reference table, and worked examples.

Millimeters to centimeters reference table

Common millimeters values with their centimeters equivalent, computed with the same factors the converter uses.

mmcm
0.10.01
20.2
70.7
111.1
161.6
242.4
363.6
505
909
20020
60060
1000100

Need a value that is not listed? Open the mm to cm converter and type any number.