🔄 Converters

Unit Converters

Instant conversion between every unit you'll ever need. Enter a value in any unit and see all others at once. Temperature, length, weight, volume, speed, area, energy, pressure, data and more.

🌡️ Temperature

Celsius to Fahrenheit

Bidirectional °C ↔ °F with Kelvin, formula, context description and reference table.

Bidirectional • Kelvin • Reference table

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin and Rankine. Enter any scale and see all four at once.

Celsius, °F, Kelvin, Rankine

📏 Length

📏

Length Converter

mm, cm, meters, km, inches, feet, yards, miles, nautical miles all in one place.

9 length units simultaneously

📏

Centimeters to Inches

Bidirectional cm ↔ inches with feet and inches output. Includes a common lengths reference table.

Bidirectional • Feet & inches

📏

Convert feet and inches to meters and centimeters. Bidirectional with reference table.

Bidirectional • Reference table

📏

Kilometers to Miles

Convert km to miles and back. Includes running distances and common reference points.

Bidirectional • Running distances

⚖️ Weight & Mass

Weight Converter

Convert between kg, pounds, grams, ounces, tons, stones and more. All units shown at once.

All weight units

Kilograms to Pounds

Convert kg to lbs and back. Includes stones and ounces. Reference table for common weights.

kg, lbs, stones • Reference

Grams to Ounces

Convert grams to ounces and back. Useful for cooking, postage, jewelry and scientific measurements.

Bidirectional • Cooking use

🥤 Volume & Cooking

🥤

Volume Converter

Liters, gallons, cups, ml, fl oz, pints, quarts, cubic meters and more. All units shown simultaneously.

14 volume units

🍳

Cooking Converter

Cups, tablespoons, teaspoons, ml, fluid ounces, pints. Ingredient weight reference for flour, sugar, butter.

Volume • Ingredient weight guide

🏃 Speed & Area

🚀

Speed Converter

Convert between km/h, mph, m/s, knots, Mach and speed of light. All conversions at once.

km/h, mph, m/s, knots, Mach

📐

Square meters, square feet, acres, hectares, km², miles² and more. All conversions simultaneously.

⚡ Energy, Pressure & Data

⚡

Energy Converter

Joules, calories, kWh, BTU, eV and more. Scientific and everyday energy units in one tool.

Joules, kWh, BTU, calories

🔧

Pressure Converter

PSI, bar, pascals, atmospheres, mmHg. Convert between all pressure units instantly.

PSI, bar, Pa, atm, mmHg

💾

Data Storage Converter

Bytes, KB, MB, GB, TB, PB. Convert between all digital storage units including bits.

Bytes to petabytes

Convert between seconds, minutes, hours, days, weeks, months and years. All time units at once.

🔢 Number Systems

Roman Numerals Converter

Convert numbers to Roman numerals and back. Supports the full range from I to MMMCMXCIX (3999).

1 to 3999 • Bidirectional