Free Unit Converters
Convert length, weight, temperature, speed, area, volume, data storage and fuel efficiency — every unit updates at once. Accurate, private and free.
Last updated: June 2026
Length Converter
Metres, feet, inches, miles, kilometres, light years and more.
Open toolWeight & Mass Converter
Kilograms, pounds, ounces, stone, grams, tonnes and carats.
Open toolTemperature Converter
Celsius, Fahrenheit, Kelvin and Rankine, with reference points.
Open toolSpeed Converter
km/h, mph, m/s, knots and Mach, with common speed references.
Open toolArea Converter
Square metres, acres, hectares, square feet and Indian land units.
Open toolVolume Converter
Litres, gallons, cups, pints and cooking measurements.
Open toolData Storage Converter
Bytes, KB, MB, GB, TB — both binary (GiB) and decimal (GB).
Open toolFuel Efficiency Converter
MPG (US/UK), L/100km, km/L — compare fuel economy units.
Open toolShoe Size Converter
US, UK, EU, CM and inches for men, women and kids, with a full chart.
Open toolMobile Data Calculator
Work out how long your data will last, or how much you need, from your streaming and browsing habits.
Open toolTry these examples
One place for every unit conversion
From following an American recipe to reading a European weather forecast or sizing a hard drive, unit conversion is a constant of daily life. CrispToolHub's free unit converters handle eight of the most common measurement categories with a single, consistent design — type into any unit and every other unit updates at the same instant, so there's no fiddly "from" and "to" to set.
The length converter spans the everyday (metres, feet, inches, miles) and the extreme (micrometres, light years and astronomical units), while the weight and mass converter covers kilograms, pounds, stone, ounces, tonnes and carats. The temperature converter moves between Celsius, Fahrenheit, Kelvin and Rankine and shows familiar reference points, and the speed converter handles km/h, mph, m/s, knots and Mach.
For property and cooking, the area converter includes acres, hectares and square feet alongside Indian land units like bigha, biswa, marla and kanal, and the volume converter translates between litres, US and UK gallons, and kitchen measures like cups, tablespoons and teaspoons. Finally, the data storage converter clarifies the binary-versus-decimal confusion behind GB and GiB, and the fuel efficiency converter compares MPG with L/100km. For shopping, the shoe size converter translates between US, UK, EU and centimetre sizes for men, women and kids. Every tool is free, instant and runs entirely in your browser — pick one above to start.
How to get started
Three quick steps — no account, nothing uploaded to a server.
Choose a tool from below
Browse the tools on this page and pick the one that fits what you need.
Use it instantly — no account needed
Open it and start right away; everything runs free in your browser.
Download or copy your results
Save, copy or share your output in a click — nothing is uploaded to a server.
FAQ
Frequently asked questions
Are these unit converters free and accurate?
Yes — every converter is completely free with no sign-up, and they use the internationally defined conversion factors (for example, exactly 0.3048 metres to the foot and 0.45359237 kilograms to the pound). All conversions happen instantly in your browser, so your figures stay private.
How do I convert between metric and imperial units?
Just type a value into any unit's box and every other unit updates at the same moment. There's no 'from' and 'to' to set — edit metres and you instantly see feet, inches, miles and the rest. It works the same way for weight, volume, area and speed.
Why are GB and GiB different sizes?
Storage uses two systems. Decimal units (KB, MB, GB) are powers of 1,000, while binary units (KiB, MiB, GiB) are powers of 1,024. So 1 GB = 1,000 MB but 1 GiB = 1,024 MiB. The data storage converter shows both side by side, which explains why a '1 TB' drive shows as roughly 931 GiB in your operating system.
Do you support Indian land measurement units?
Yes. The area converter includes bigha, biswa, marla and kanal alongside acres, hectares and square feet. Note that some Indian land units vary by region — the converter uses widely accepted standard values, so check your local convention for legal or property use.
How does fuel efficiency conversion work?
Fuel economy units relate inversely: a higher MPG means lower L/100km. The fuel converter handles US MPG, UK MPG, litres per 100 km and kilometres per litre, converting correctly between the 'distance per fuel' and 'fuel per distance' styles so you can compare cars sold in different markets.