Unit Converter Calculator - Convert Any Unit Instantly
Use our free unit converter to convert km to miles, kg to pounds, Celsius to Fahrenheit, liters to gallons, and 90+ other units. Enter your value and get instant results with conversion formulas. Perfect for students, travelers, engineers, and everyday calculations.
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Quick Conversions
Conversion Result
1 m = 0 ft
Conversion Formula
1 Meter = 3.2808399 Foot
What is a Unit Converter Calculator?
A unit converter calculator is an essential tool that translates measurements from one unit system to another. In a world where the metric system (meters, kilograms, Celsius) and imperial system (feet, pounds, Fahrenheit) coexist, unit conversion is a daily necessity for millions of people worldwide.
Our free online unit converter supports 10 different measurement categories with over 90 unit types. From simple conversions like km to miles or kg to lbs, to specialized calculations like Pascal to PSI or joules to calories, this tool handles it all with scientific precision.
Unlike basic converters, our tool shows the conversion formula for each calculation, helping you understand the math behind the conversion. You can also save your conversions to history, swap units instantly, and copy results with one click.
10 Unit Conversion Categories
Length Converter
Convert meters, kilometers, miles, feet, inches, yards, and more.
Weight Converter
Convert kilograms, pounds, ounces, grams, stones, and tons.
Temperature Converter
Convert Celsius, Fahrenheit, Kelvin, and Rankine temperatures.
Volume Converter
Convert liters, gallons, milliliters, cups, pints, and fluid ounces.
Area Converter
Convert square meters, acres, hectares, square feet, and square miles.
Speed Converter
Convert km/h, mph, m/s, knots, and Mach speed units.
Time Converter
Convert seconds, minutes, hours, days, weeks, months, and years.
Data Storage Converter
Convert bytes, KB, MB, GB, TB, PB, and binary units (KiB, MiB).
Energy Converter
Convert joules, calories, kilocalories, kWh, BTU, and electronvolts.
Pressure Converter
Convert Pascal, PSI, bar, atmosphere, torr, and mmHg.
Common Unit Conversion Formulas
Length Conversions
Weight Conversions
Temperature Conversions
Volume Conversions
Why Use Our Unit Converter Calculator?
10 Categories
Length, weight, temperature, volume, area, speed, time, data, energy, and pressure.
90+ Units
From common units like meters and pounds to specialized units like Pascals and electronvolts.
$0 Cost
100% free forever. No signup, no hidden fees, no premium features locked away.
Shows Formulas
Learn the conversion formula for every calculation. Great for students and learning.
Swap & Copy
One-click to swap units or copy results. Quick conversions with history tracking.
Mobile Friendly
Fully responsive design. Convert units on your phone, tablet, or desktop anywhere.
Unit Conversion Guides
Complete Unit Conversion Guide 2025
Master unit conversions with our comprehensive guide. Learn formulas, tips, and common conversion factors for all measurement types.
Metric vs Imperial Units - Complete Comparison Guide
Understand the differences between metric and imperial measurement systems. Learn which countries use what and how to convert between them.
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Frequently Asked Questions
How do I convert kilometers to miles?
To convert kilometers to miles, multiply by 0.621371. For example, 10 km × 0.621371 = 6.21 miles. Our converter does this automatically - select Length category, choose kilometers and miles, enter your value.
How do I convert Celsius to Fahrenheit?
Use the formula: °F = (°C × 9/5) + 32. For example, 25°C = (25 × 1.8) + 32 = 77°F. Our temperature converter handles this instantly with just two clicks.
How many pounds are in a kilogram?
1 kilogram = 2.20462 pounds. To convert kg to lbs, multiply by 2.20462. Example: 70 kg × 2.20462 = 154.32 lbs. To convert lbs to kg, divide by 2.20462.
How do I convert liters to gallons?
For US gallons: 1 liter = 0.264172 gallons. Multiply liters by 0.264172. For UK (imperial) gallons: 1 liter = 0.219969 gallons. Our converter supports both US and UK gallons.
What's the difference between metric and imperial units?
Metric units (SI) use base-10 (meters, kilograms, liters) and are used in most countries. Imperial units (feet, pounds, gallons) use non-decimal conversions and are primarily used in the US. Our converter supports both systems.
Is this unit converter free?
Yes! Our unit converter calculator is 100% free with no signup required. All 10 categories and 90+ unit types are available at no cost. Convert as many units as you need without any limitations.