Length Converter

How to use Length Converter

Enter your measurement value

Type the number you want to convert (e.g. 5.8 or 100). Decimal values and large numbers are both supported.

Select the input unit

Choose the unit your measurement is currently in: millimetres (mm), centimetres (cm), metres (m), kilometres (km), inches (in), feet (ft), yards (yd), or miles (mi).

Read the converted values

All equivalent measurements update instantly in a table. Copy any value directly from the result table.

Use the reverse direction

To convert in the other direction, simply change the input unit selection. The value field retains your number so you can quickly explore multiple conversions.

Length Converter examples

Convert height from feet to centimetres

Input

5 feet 10 inches (5.833 ft)

Output

177.8 cm · 1.778 m · 1,778 mm

5 feet 10 inches = 5 + (10/12) = 5.833 feet. 5.833 × 30.48 cm/ft = 177.8 cm. Height conversion is the most common use case for this tool.

Convert a marathon distance

Input

26.2 miles

Output

42.195 km · 42,195 m

The exact marathon distance is 42.195 km. Common knowledge states it as 26.2 miles or 42.2 km — the precise figure is 26.2188 miles = 42.195 km.

Convert room dimensions for furniture planning

Input

12 feet

Output

144 inches · 365.76 cm · 3.658 m

A 12 × 10 foot room is 3.658 × 3.048 metres. IKEA and European furniture catalogues list dimensions in cm/m, so this conversion is needed when planning international furniture purchases.

Who uses Length Converter?

Common real-world scenarios where this tool saves time.

International travellers and expats

Convert between metric and imperial systems

Road signs in the UK use miles; in Europe they use kilometres. Speed limits, distances, and heights switch between systems depending on country. Quick length conversion avoids estimation errors.

Construction and home improvement

Convert between drawing units and real-world measurements

Architectural plans often use millimetres (UK/EU standard). Contractors and DIYers in the US work in feet and inches. Converting accurately prevents costly material ordering mistakes.

Fitness and sports

Convert race distances and training metrics

Running apps use kilometres; US-focused apps default to miles. Convert 5K (3.107 mi), 10K (6.214 mi), half marathon (13.109 mi), and marathon (26.219 mi) distances for race registration and training plans.

Common mistakes to avoid

Confusing 'metres' and 'yards' as approximately equal

1 yard = 0.9144 metres — they are close but not the same. A 100-yard football field is 91.44 metres, not 100 metres. In precision contexts (science, manufacturing) use the exact conversion factor.

Converting height in feet and inches as a decimal incorrectly

5'10" is not 5.10 feet — it is 5 + (10/12) = 5.833 feet. Convert the inches portion separately: 10 inches ÷ 12 = 0.833 feet, then add to 5. Enter 5.833 (not 5.10) for accurate cm conversion.

Using rounded conversion factors for engineering calculations

1 inch = exactly 2.54 cm (defined). 1 foot = exactly 30.48 cm. 1 mile = exactly 1.60934 km. For casual use, 1 mile ≈ 1.6 km is fine. For technical or scientific work, always use the exact defined values.

Frequently Asked Questions

How many centimetres are in an inch?

Exactly 2.54 centimetres per inch. This is a defined conversion (not measured), so it is exact: 1 in = 2.54 cm exactly. This makes 1 foot = 12 × 2.54 = 30.48 cm, and 1 yard = 91.44 cm.

How do I convert feet and inches to centimetres?

Convert the feet to inches first (multiply by 12), add the remaining inches, then multiply the total inches by 2.54. Example: 5'10" = (5 × 12) + 10 = 70 inches. 70 × 2.54 = 177.8 cm.

How many metres in a mile?

1 mile = 1,609.344 metres (exactly), or 1.609344 kilometres. The rounded commonly-used values: 1 mile ≈ 1.6 km (3% underestimate), 1 km ≈ 0.621 miles.

What is the difference between a nautical mile and a regular mile?

A statute mile (regular mile) = 1,609.344 metres. A nautical mile = 1,852 metres. Nautical miles are used in aviation and maritime navigation because 1 nautical mile corresponds to 1 minute of arc of latitude on the Earth's surface, making chart navigation calculations simpler.

Is a yard the same as a metre?

No. 1 yard = 0.9144 metres. They are close enough that casual comparisons work, but for precision (engineering, sport records, athletics) use the exact conversion. A 100-metre sprint is 109.36 yards — about 9.4% longer than 100 yards.

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Length Conversion Information

How to use Length Converter

Enter your measurement value

Select the input unit

Read the converted values

Use the reverse direction