All Tools Verse
The best free online unit converters turn one measurement into another instantly, from kilograms to pounds or Celsius to Fahrenheit, all in your browser. All Tools Verse has a full set of free unit converters that run client-side with no sign-up. This guide picks the best free tool for each kind of unit, from everyday length and weight to data storage and engineering units.
In this guide
Everyday units
The units people convert most: Length Converter for metric and imperial distance, Weight Converter for kilograms and pounds, Temperature Converter for Celsius, Fahrenheit, and Kelvin, Volume Converter for liters and gallons, Area Converter for square meters and acres, and Speed Converter for km/h and mph.
Data and digital
For computing, Data Storage Converter moves between MB, GB, MiB, and GiB, Data Transfer Rate Converter turns Mbps into MB/s, and Frequency Converter handles Hz, kHz, MHz, and GHz.
Science and engineering
For technical work, Energy Converter covers joules, calories, and kWh, Power Converter covers watts and horsepower, Pressure Converter covers bar, PSI, and kPa, and Angle Converter covers degrees, radians, and gradians.
Travel and time
For trips, Fuel Economy Converter switches between MPG and L per 100 km, and Time Converter moves between seconds, minutes, hours, and days.
Trusted alternatives
Google search converts common units if you type the query directly, and your phone may have a units app built in. For science, a reference table or a tool like Wolfram Alpha covers rare units. For a quick everyday conversion, a focused browser tool is clear and fast.
Popular free tools in this guide
Frequently asked questions
How do I convert kilograms to pounds?
Use Weight Converter, enter the value in kilograms, and it returns pounds and other units instantly in your browser.
How do I convert Celsius to Fahrenheit?
Temperature Converter switches between Celsius, Fahrenheit, and Kelvin, so you can go in any direction.
How do I convert MB to GB?
Data Storage Converter moves between MB, GB, and the binary MiB and GiB units, which matters for accurate file sizes.
How do I convert mph to km/h?
Speed Converter handles km/h, mph, m/s, and knots, so you can switch between any two.
Are these converters free and private?
Yes. Every tool is free with no account, and the calculation runs on your device, so nothing you enter is uploaded.
This guide is part of our roundup of the best free online tools.