100% Local

Unit Converter

Convert between hundreds of units across 10 categories: length, weight, temperature, area, volume, speed, time, data, pressure and energy — all calculated locally.

Formula:1 mm = 0.1 cm

All conversions

ToFrom1 mm
mm1
cm0.1
m0.001
km0.000001
in0.03937007874
ft0.003280839895
yd0.001093613298
mi6.213712e-7

🔒 All calculations happen locally — no data is sent to any server

100% secure

Your files are never shared

Ultra-fast

Processing in seconds

Privacy

Automatic deletion after 1h

How to use the Unit Converter

1

Choose a category

Select a conversion category from the tabs: Length, Weight, Temperature, Area, Volume, Speed, Time, Data, Pressure, or Energy.

2

Enter your value

Type the value you want to convert and select the source and target units from the dropdown menus. The result updates instantly.

3

View all conversions

See the quick reference table below for your value converted to every unit in the category. The formula used for the conversion is also displayed.

Common Length Conversions

FromToFactor
1 km0.621371 mi× 0.621371
1 mi1.60934 km× 1.60934
1 in2.54 cm× 2.54
1 ft30.48 cm× 30.48
1 yd0.9144 m× 0.9144

Temperature Conversion Formulas

Temperature conversions use special formulas rather than simple multiplication factors. Celsius to Fahrenheit: °F = °C × 9/5 + 32. Fahrenheit to Celsius: °C = (°F − 32) × 5/9.

For Kelvin conversions: K = °C + 273.15 and °C = K − 273.15. Kelvin is the SI unit of temperature and starts at absolute zero (−273.15°C).

Data Units: Base-1000 vs Base-1024

In computing, there are two systems for measuring data: base-1000 (SI: KB, MB, GB) and base-1024 (binary: KiB, MiB, GiB). Hard drive manufacturers typically use base-1000, while operating systems often use base-1024.

This is why a '500 GB' hard drive shows as approximately 465 GiB in your operating system. Our converter supports both systems so you can convert between them accurately.

Privacy & Security

All unit conversions are calculated locally in your browser. No data is transmitted to any server. This tool works fully offline once loaded.

Unit ConverterFrequently asked questions

How do I convert kilometers to miles?

Select the 'Length' category, enter your value in kilometers, and select miles as the target unit. The conversion happens instantly: 1 kilometer equals approximately 0.621371 miles.

How do I convert Celsius to Fahrenheit?

Select the 'Temperature' category, enter your Celsius value, and select Fahrenheit. The formula is: °F = °C × 9/5 + 32. For example, 100°C = 212°F.

How many grams are in a pound?

One pound (lb) equals exactly 453.592 grams. Select the 'Weight' category and convert between lb and g instantly.

How do I convert inches to centimeters?

Select 'Length', enter your value in inches, and select centimeters. The conversion factor is: 1 inch = 2.54 cm exactly.

What is the difference between KB and KiB?

KB (kilobyte) uses base-1000 (1 KB = 1,000 bytes), while KiB (kibibyte) uses base-1024 (1 KiB = 1,024 bytes). Our tool supports both systems in the Data category.

How do I convert pressure units?

Select the 'Pressure' category to convert between Pascals, kilopascals, bar, atmospheres, PSI, and mmHg. All conversions are calculated using standard conversion factors.

Does the converter show formulas?

Yes! Below the conversion result, the tool displays the formula used for the conversion, along with a quick reference table showing your value converted to all units in the selected category.

Is my data private?

Yes. All calculations are performed locally in your browser using JavaScript. No data is ever sent to a server.

Similar tools