Length & Distance Converter
Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards, and miles.
Enter a length value and select the unit to see instant conversions to all other units.
Millimetres (mm)
1,000 mm
Centimetres (cm)
100 cm
Kilometres (km)
0.001 km
Inches (in)
39.370079 in
Feet (ft)
3.28084 ft
Yards (yd)
1.093613 yd
Miles (mi)
0.000621 mi
The One Number That Connects Everything
In 1959, the international yard was defined as exactly 0.9144 metres. From that single agreement, every imperial-to-metric length conversion follows with zero rounding. One inch is exactly 25.4 mm. One foot is exactly 304.8 mm. One mile is exactly 1,609.344 metres. These aren't approximations, they're definitions.
Most of the world runs on metric. The US, Liberia, and Myanmar are the holdouts. The UK sits somewhere in between, road signs in miles, height in feet and inches, but construction and medicine in metres and millimetres. This converter handles all of it instantly.
Conversion Quick Reference
| From | To | Multiply by | Example |
|---|---|---|---|
| Inches | Centimetres | 2.54 | 12 in = 30.48 cm |
| Feet | Metres | 0.3048 | 6 ft = 1.829 m |
| Yards | Metres | 0.9144 | 100 yd = 91.44 m |
| Miles | Kilometres | 1.60934 | 26.2 mi = 42.16 km |
| Centimetres | Inches | 0.3937 | 170 cm = 66.93 in |
| Metres | Feet | 3.2808 | 1.8 m = 5.91 ft |
| Kilometres | Miles | 0.6214 | 10 km = 6.21 mi |
Mental math shortcut: For km to miles, multiply by 5 and divide by 8. So 80 km × 5 ÷ 8 = 50 miles. For miles to km, multiply by 8 and divide by 5. Both get you within 0.5% of the exact answer.
Height Conversion Table
The conversion people look up most. Feet/inches to centimetres for every common adult height:
| Feet & Inches | Centimetres | Metres |
|---|---|---|
| 5'0" | 152.4 | 1.524 |
| 5'2" | 157.5 | 1.575 |
| 5'4" | 162.6 | 1.626 |
| 5'6" | 167.6 | 1.676 |
| 5'8" | 172.7 | 1.727 |
| 5'10" | 177.8 | 1.778 |
| 6'0" | 182.9 | 1.829 |
| 6'2" | 188.0 | 1.880 |
| 6'4" | 193.0 | 1.930 |
The formula: (feet × 30.48) + (inches × 2.54) = total centimetres. So 5'8" = (5 × 30.48) + (8 × 2.54) = 152.4 + 20.32 = 172.72 cm.
Real-World Distances That Help You Visualise
Thickness of a credit card. About 0.04 inches.
Width of a pencil. About 0.4 inches, slightly less than half an inch.
Width of your thumb at the knuckle. Exactly 2.54 cm.
Length of a standard ruler. 30.48 cm. Roughly the length of your forearm from wrist to elbow.
A large stride. About 3 feet 3 inches. A kitchen worktop is roughly 90 cm high, a door handle about 1 m.
A 12-minute walk for most adults. 0.621 miles. About 3,281 feet.
A 20-minute walk. 1.609 km. 5,280 feet. Four laps of a standard running track.
The UK's Hybrid Measurement System
If you live in the UK, you already switch between systems without thinking about it. Here's the actual breakdown of what British people use in practice:
Uses Imperial
- Road distances and speed limits (miles, mph)
- Personal height (feet and inches)
- Beer and cider (pints)
- Screen sizes (inches, globally standard)
Uses Metric
- Construction and DIY (millimetres, metres)
- Medicine and science (mm, cm, m)
- Product labels and packaging (ml, g, cm)
- Running races (5K, 10K, marathon in km)
This is why a converter matters for UK users more than almost anyone else. You'll need to go from feet to metres for a building plan, then from miles to km when entering a race, all in the same week.
Related Tools
How to use this tool
Enter the length or distance value
Select the source unit from the dropdown
View instant conversions to all other length units
Common uses
- Converting height between feet/inches and centimetres
- Calculating room dimensions for international furniture
- Converting running distances between km and miles
- Estimating travel distances in unfamiliar unit systems
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Frequently Asked Questions
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