How many centimetres are in an inch?

There are exactly 2.54 centimetres in one inch. This is the defined relationship between the metric and imperial length systems.

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

A nautical mile is 1852 metres, while a statute mile is 1609.344 metres. Nautical miles are used in aviation and maritime navigation because one nautical mile equals one arcminute of latitude.

How do I convert feet and inches to centimetres?

First convert feet to inches (1 ft = 12 in), add your remaining inches, then multiply the total inches by 2.54 to get centimetres. For example, 5 ft 9 in = 69 in = 175.26 cm.

What is a light year in kilometres?

One light year is approximately 9.461 × 10^12 kilometres. It is the distance light travels in one year in a vacuum and is used to express astronomical distances.

Why does the converter show scientific notation for some results?

When a result is extremely large or very close to zero, scientific notation keeps the display readable. For example, converting 1 metre to light years gives roughly 1.057 × 10^-16 ly.

Conversions

↵ to calculate

Length Converter — Inches Feet Meters CM MM online

Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, and more.

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How to use this calculator

👉 Fill in the boxes below and your answer appears instantly — no maths needed, we do it all for you! 🎉

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In plain English — what does this do?

📏 Some countries say ‘30 degrees’ and others say ‘86 degrees’ for the same weather! Some say ‘5 km’, others say ‘3 miles’. This tool swaps between them instantly so you always know what it means.

📌 Direct Answer & Summary

A length converter lets you instantly convert a distance or size measurement from one unit to another. Length is a fundamental physical quantity measured in SI units (metres) as well as imperial and US customary units like feet and inches. Conversions are needed whenever you work across systems — for example, reading a blueprint in millimetres while your tape measure shows inches.

Value

From

What is Length Converter — Inches Feet Meters CM MM online?

How to use it

1️⃣ Enter the numeric value you want to convert in the Value field.
2️⃣ Select the unit you are converting from in the From dropdown.
3️⃣ Select the unit you want to convert to in the To dropdown.
4️⃣ The result appears instantly below the inputs.
5️⃣ Use the swap button to reverse the conversion direction.

Formula

converted = input_value * (factor_of_from_unit / factor_of_to_unit), where all factors are expressed relative to metres

💡 See it in action — a real example

To convert 5 miles to kilometres: 5 miles × 1609.344 m/mi = 8046.72 m, then 8046.72 m / 1000 m/km = 8.047 km. So 5 miles is approximately 8.05 kilometres.

❓ Common questions

How many centimetres are in an inch?: There are exactly 2.54 centimetres in one inch. This is the defined relationship between the metric and imperial length systems.
What is the difference between a nautical mile and a regular mile?: A nautical mile is 1852 metres, while a statute mile is 1609.344 metres. Nautical miles are used in aviation and maritime navigation because one nautical mile equals one arcminute of latitude.
How do I convert feet and inches to centimetres?: First convert feet to inches (1 ft = 12 in), add your remaining inches, then multiply the total inches by 2.54 to get centimetres. For example, 5 ft 9 in = 69 in = 175.26 cm.
What is a light year in kilometres?: One light year is approximately 9.461 × 10^12 kilometres. It is the distance light travels in one year in a vacuum and is used to express astronomical distances.
Why does the converter show scientific notation for some results?: When a result is extremely large or very close to zero, scientific notation keeps the display readable. For example, converting 1 metre to light years gives roughly 1.057 × 10^-16 ly.

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