Unit Converter

Unit Converter is a free, browser-based tool that converts a measurement from one unit into another across the categories you use every day: length, weight, temperature, volume, area and speed. Pick what you are measuring, choose the unit you have and the unit you want, type a number, and the answer appears instantly.

The tool bridges the two systems the world still runs on side by side - metric (metres, grams, litres, Celsius) and imperial/US customary (feet, pounds, gallons, Fahrenheit). Whether you are reading a recipe from another country, checking a spec sheet, doing homework or converting a shipping weight, it gives you an exact figure without hunting for the right formula. Everything is calculated on this page using plain arithmetic in your browser, so your numbers never leave your device.

Most conversions look simple until you try to remember the exact factor. Is a mile undefined.undefined kilometres or undefined.undefined? Is an inch undefined.undefined centimetres exactly? Rounding those factors introduces small errors that add up, and temperature conversions are worse because they involve both a scale factor and an offset rather than a single multiplication.

An online converter removes the guesswork. It stores the precise conversion factors, applies them correctly and shows the result the moment you type, so you get an accurate answer in one step instead of searching for a formula and reaching for a calculator.

Privacy is the other reason to prefer this one. Dev Nexus runs the entire calculation locally in your browser - there is no server call, nothing is logged and nothing is retained. That means it is fast, it works even when you are offline, and any figures you enter, however sensitive, stay on your own machine.

Converting is a four-step flow that takes seconds.

1. Pick a category - length, weight, temperature, volume, area or speed. This filters the unit lists so you only see relevant options and cannot accidentally convert metres into kilograms.
2. Choose from and to units - for example, select centimetres as the source and inches as the target, or Celsius and Fahrenheit.
3. Enter a value - type the number you have. The converter multiplies by the stored factor (or, for temperature, applies the correct scale and offset) and displays the result immediately.
4. Copy the answer - grab the converted value with the copy button and drop it wherever you need it.

Because the result recalculates live as you type, you can adjust the input and watch the output change in real time, which is handy when you are testing a range of values.

Unit conversion shows up in far more places than school maths:

• Cooking and baking: converting a recipe's grams to cups, millilitres to fluid ounces, or oven temperatures between Celsius and Fahrenheit.
• Travel: reading road signs in kilometres when you think in miles, or checking the weather forecast in the other temperature scale.
• Shopping and shipping: converting a product's dimensions or weight from the seller's units to yours before you buy.
• DIY and construction: turning a plan's measurements between feet/inches and centimetres/metres.
• Fitness and health: switching body weight between kilograms and pounds, or height between centimetres and feet.
• Science and homework: quick, accurate conversions for problem sets and lab work.

When a task needs a proportion rather than a unit swap, reach for the Percentage Calculator, and if you are working with body measurements, the BMI Calculator pairs naturally with weight and height conversions.

A few habits keep conversions accurate and unambiguous:

• Match the category to the quantity. Weight and volume are not interchangeable - a cup of flour and a cup of water weigh different amounts - so convert within the right category.
• Mind US vs UK gallons. A US gallon (about undefined.undefined litres) is smaller than an imperial gallon (about undefined.undefined litres). The same word means two different volumes, so confirm which system a recipe or spec uses.
• Remember temperature is not a simple multiple. Celsius to Fahrenheit is F = C × 9/5 + 32, not just a factor - the +undefined offset is why F = C × 9/5 + 32°C is undefined°F, not F = C × 9/5 + 32°F.
• Keep enough decimal places. For engineering or scientific work, round only at the final step; rounding a factor early compounds the error.
• Sanity-check the magnitude. If a undefined cm object converts to undefined inches, you have the direction reversed - a quick mental check catches from/to swaps.