# Imperial to Metric Converter

URL: https://speedycalculator.com/calculators/conversion/imperial-to-metric-conversion/
Last updated: 2026-10-25

> The imperial to metric converter handles the everyday conversions in one place: inches to centimetres, feet to metres, miles to kilometres, pounds to kilograms, ounces to grams, gallons to litres and Fahrenheit to Celsius.

## Inputs

- Inches
- Feet
- Miles
- Pounds
- Ounces
- US gallons
- Fahrenheit

## Results

- Inches in centimetres
- Feet in metres
- Miles in kilometres
- Pounds in kilograms
- Ounces in grams
- Gallons in litres
- Fahrenheit in Celsius

## Formula

```
cm = in × 2.54;  m = ft × 0.3048;  km = mi × 1.609344
kg = lb × 0.45359237;  g = oz × 28.3495;  L = US gal × 3.78541;  °C = (°F − 32) × 5/9
```

## Explanation

Imperial and U.S. customary units are still used for many everyday measures in the U.S. and UK. All of the factors here are exact definitions except the rounded display.

### How to use the Imperial to Metric Converter

- **Inches**
- **Feet**
- **Miles**
- **Pounds**
- **Ounces**
- **US gallons**
- **Fahrenheit**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Each input is converted independently, so fill in only what you need.

### Inputs explained

FieldWhat to enterInchesA numberFeetA numberMilesA numberPoundsA numberOuncesA numberUS gallonsA numberFahrenheitA number

### What each result means

- **Inches in centimetres** = [Inches] × 2.54
- **Feet in metres** = [Feet] × 0.3048
- **Miles in kilometres** = [Miles] × 1.609344
- **Pounds in kilograms** = [Pounds] × 0.45359237
- **Ounces in grams** = [Ounces] × 28.349523125
- **Gallons in litres** = [US gallons] × 3.785411784
- **Fahrenheit in Celsius** = ([Fahrenheit] - 32) × 5 ÷ 9

### Example values

How the main result changes when **Inches** changes and everything else stays at the example values above:

InchesPounds in kilograms (kg)668.039968.0391268.0391568.0391868.0392468.039

## Worked example

Inputs — Inches: 12; Feet: 6; Miles: 10; Pounds: 150; Ounces: 8; US gallons: 5; Fahrenheit: 98.6.

Results — Inches in centimetres = 30.48 cm; Feet in metres = 1.8288 m; Miles in kilometres = 16.093 km; **Pounds in kilograms = 68.039 kg**; Ounces in grams = 226.8 g; Gallons in litres = 18.927 L; Fahrenheit in Celsius = 37 °C.

## FAQ

**Is the UK still imperial?**
Officially metric, but miles, pints and stones remain in everyday use.

**Are U.S. and UK gallons the same?**
No: the UK gallon is 4.546 L, the U.S. gallon 3.785 L.

**What formula does the Imperial to Metric Converter use?**
cm = in × 2.54;  m = ft × 0.3048;  km = mi × 1.609344.


## Sources

- [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)