Understanding Length Units

Metric System (SI)

Millimeter (mm) = 0.001 m
Centimeter (cm) = 0.01 m
Meter (m) = Base unit
Kilometer (km) = 1000 m

Imperial/US System

Inch (in) = 2.54 cm
Foot (ft) = 12 inches
Yard (yd) = 3 feet
Mile (mi) = 1760 yards

Common Conversions

From	To	Multiply By
Inches	Centimeters	2.54
Feet	Meters	0.3048
Yards	Meters	0.9144
Miles	Kilometers	1.60934

Practical Examples

Construction

Standard door height: 80 inches = 203.2 centimeters

Room width: 12 feet = 3.66 meters

Sports

Football field: 100 yards = 91.44 meters

Basketball hoop height: 10 feet = 3.048 meters

Understanding Length Units

Metric System (SI)

Millimeter (mm)
Centimeter (cm)
Meter (m)
Kilometer (km)

Imperial/US System

Inch (in)
Foot (ft)
Yard (yd)
Mile (mi)

Metric Units in Detail

Millimeter (mm)

The smallest commonly used metric unit for length. Equal to 0.001 meters.

1 mm = 0.1 cm = 0.001 m

Example uses: Paper thickness, electronic components, precision measurements

Centimeter (cm)

A common unit for everyday measurements. Equal to 0.01 meters.

1 cm = 10 mm = 0.01 m

Example uses: Body measurements, small object dimensions, short distances

Meter (m)

The base unit of length in the metric system.

1 m = 100 cm = 1000 mm

Example uses: Room dimensions, human height, furniture sizes

Kilometer (km)

Used for longer distances. Equal to 1000 meters.

1 km = 1000 m = 100000 cm

Example uses: Road distances, city planning, geographic measurements

Imperial/US Units in Detail

Inch (in)

The smallest commonly used imperial unit for length.

1 inch = 2.54 cm = 25.4 mm

Example uses: Screen sizes, lumber dimensions, rainfall measurements

Foot (ft)

Equal to 12 inches.

1 foot = 12 inches = 30.48 cm

Example uses: Human height, room dimensions, altitude measurements

Yard (yd)

Equal to 3 feet or 36 inches.

1 yard = 3 feet = 91.44 cm

Example uses: Fabric measurements, sports field dimensions, short distances

Conversion Formulas and Tables

Metric to Imperial Conversions

From	To	Formula	Example
Centimeters	Inches	cm ÷ 2.54	25.4 cm = 10 inches
Meters	Feet	m × 3.281	1 m = 3.281 feet
Meters	Yards	m × 1.094	10 m = 10.94 yards
Kilometers	Miles	km × 0.621	5 km = 3.11 miles

Imperial to Metric Conversions

From	To	Formula	Example
Inches	Centimeters	in × 2.54	10 inches = 25.4 cm
Feet	Meters	ft × 0.3048	6 feet = 1.83 meters
Yards	Meters	yd × 0.9144	10 yards = 9.14 meters
Miles	Kilometers	mi × 1.609	5 miles = 8.05 kilometers

Common Conversions Chart

Length	Metric Equivalent	Imperial Equivalent
1 millimeter	0.1 centimeter	0.039 inches
1 centimeter	10 millimeters	0.394 inches
1 meter	100 centimeters	3.281 feet
1 kilometer	1000 meters	0.621 miles
1 inch	2.54 centimeters	1/12 foot
1 foot	30.48 centimeters	12 inches
1 yard	91.44 centimeters	3 feet
1 mile	1.609 kilometers	1760 yards

Popular Length Unit Conversions

From	To	Result	Details
237 Feet	Inches	2,844.00 Inches	View Calculation →
251 Centimeters	Meters	2.51 Meters	View Calculation →
317 Meters	Inches	12,480.32 Inches	View Calculation →
383 Yards	Inches	13,788.00 Inches	View Calculation →
346 Inches	Centimeters	878.84 Centimeters	View Calculation →
240 Kilometers	Yards	262,466.40 Yards	View Calculation →
196 Kilometers	Meters	196,000.00 Meters	View Calculation →
447 Kilometers	Feet	1,466,535.48 Feet	View Calculation →
974 Inches	Feet	81.17 Feet	View Calculation →
569 Centimeters	Inches	224.02 Inches	View Calculation →

Practical Examples and Usage

Home Improvement

Room dimensions: 12 feet × 15 feet = 3.66 meters × 4.57 meters

Wall height: 8 feet = 2.44 meters

Door width: 36 inches = 91.44 centimeters

Sports

Football field length: 100 yards = 91.44 meters

Olympic pool length: 50 meters = 164.04 feet

Basketball hoop height: 10 feet = 3.048 meters

Travel

Flight altitude: 35,000 feet = 10.668 kilometers

Highway distance: 100 miles = 160.93 kilometers

Walking distance: 2 kilometers = 1.24 miles