Our free conversion calculator converts between units across 8 measurement categories — length, weight and mass, temperature, area, volume, speed, digital storage, and energy. Simply select a category, enter your value and starting unit, and instantly see conversions to all other units in that category at once.

Unit conversion is a daily necessity in science, engineering, cooking, construction, and everyday life — especially in North America where imperial and metric units are both commonly used. This conversion calculator makes switching between any units effortless and error-free.

How to Use the Conversion Calculator

Converting units takes just a few seconds:

1. Select a measurement category from the dropdown (length, weight, temperature, etc.).
2. Enter your value in the number field.
3. Select your starting unit from the From dropdown.
4. Select your target unit from the To dropdown.
5. Results appear instantly — all units in the category are shown in the table below.

When Should You Use a Conversion Calculator?

Use the conversion calculator whenever you encounter a measurement in an unfamiliar unit. In particular, it is essential for anyone working between imperial and metric systems — a common situation in the USA and Canada where both systems are in regular use. Furthermore, students and scientists use it daily for unit conversions in chemistry, physics, and engineering calculations.

Additionally, travellers use it to convert between local measurement systems — for example, Americans driving in Canada need to convert km/h speed limits to mph. Moreover, cooks and bakers use it when following recipes from different countries with different measurement conventions.

Key Unit Conversions to Know

Here are the most commonly needed unit conversions in everyday life:

• Length: 1 inch = 2.54 cm | 1 foot = 30.48 cm | 1 mile = 1.609 km | 1 metre = 3.281 feet
• Weight: 1 pound = 453.6 grams | 1 kilogram = 2.205 pounds | 1 ounce = 28.35 grams
• Temperature: °F to °C: subtract 32, multiply by 5/9. °C to °F: multiply by 9/5, add 32.
• Volume: 1 US gallon = 3.785 litres | 1 litre = 33.81 fl oz | 1 cup = 236.6 ml
• Speed: 1 mph = 1.609 km/h | 100 km/h ≈ 62 mph

Frequently Asked Questions About the Conversion Calculator

How do I convert Celsius to Fahrenheit?

Use the formula: °F = (°C × 9/5) + 32. For example, 100°C = (100 × 1.8) + 32 = 212°F. To convert the other way: °C = (°F – 32) × 5/9. Our conversion calculator handles this automatically.

How many kilometers are in a mile?

1 mile = exactly 1.60934 kilometres. Conversely, 1 kilometre = 0.62137 miles. A quick approximation: multiply km by 0.6 to get miles, or multiply miles by 1.6 to get km.

Related Calculators

Furthermore, you might find these related tools useful: Scientific Calculator — Concrete Calculator