Temperature Converter 🌡️
Free online temperature converter. Convert Celsius to Fahrenheit, Fahrenheit to Celsius, Kelvin and all temperature units instantly. C to F calculator with formulas.
📐 Conversion Formula
Common Temperature Conversions
Quick Temperature Conversions
C to F
°F = °C × 9/5 + 32
20°C = 68°F
F to C
°C = (°F - 32) × 5/9
68°F = 20°C
C to K
K = °C + 273.15
0°C = 273.15 K
K to C
°C = K - 273.15
273.15 K = 0°C
Converter Performance Metrics
How to Use Temperature Converter
Step 1: Enter Temperature Value
Type the temperature value you want to convert in the "From" field. The converter accepts any number including negatives and decimals. For example, enter 20 for 20°C or 98.6 for 98.6°F depending on your selected unit.
Step 2: Select Source Unit
Choose the unit of your input temperature from the "From" dropdown. Options include Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur. Select the unit that matches your thermometer or weather report.
Step 3: Select Target Unit
Pick the unit you want to convert to from the "To" dropdown. The conversion happens automatically in real-time as you change units. The formula used for conversion is displayed below for educational reference.
Step 4: Use Results
View the converted result in the "To" field. Click Copy to copy the result to clipboard, Swap to reverse conversion direction, or Reset to start over. All calculations are instant and accurate for science and everyday use.
Understanding Temperature Scales
What is Temperature?
Temperature measures hotness or coldness of matter—average kinetic energy of particles. Higher temperature = faster molecular motion. Three main scales: Celsius (metric), Fahrenheit (USA), Kelvin (scientific). Water freezes at 0°C/32°F/273.15K, boils at 100°C/212°F/373.15K. Temperature determines state of matter, chemical reaction rates, and biological processes.
Conversion Formulas: Celsius to Fahrenheit: \( °F = °C \times \frac{9}{5} + 32 \) or \( °F = °C \times 1.8 + 32 \). Fahrenheit to Celsius: \( °C = (°F - 32) \times \frac{5}{9} \). Celsius to Kelvin: \( K = °C + 273.15 \). Kelvin to Celsius: \( °C = K - 273.15 \). Key reference: -40°C = -40°F (equal point), absolute zero = -273.15°C = -459.67°F = 0 K.
Common Temperature Scales Explained
Celsius (°C): Metric scale developed by Anders Celsius (1742). Water freezes at 0°C, boils at 100°C. Used worldwide except USA. Room temperature ~20°C, body temperature 37°C. Logical, decimal-based. Originally called centigrade (100 divisions). Standard in weather forecasts, cooking (outside USA), science education globally.
Fahrenheit (°F): Scale developed by Daniel Fahrenheit (1724). Water freezes at 32°F, boils at 212°F. Used primarily in USA, some Caribbean countries. Room temperature ~68°F, body temperature 98.6°F. More divisions between freezing/boiling (180° vs 100°). Historical reasons for continued USA use. Weather, cooking, everyday USA measurements.
Kelvin (K): Absolute thermodynamic scale. Developed by Lord Kelvin (1848). Zero point at absolute zero (-273.15°C)—coldest possible temperature where molecular motion stops. Same degree size as Celsius but different starting point. SI unit for temperature. Used in physics, chemistry, astronomy, engineering. No degree symbol—just K not °K. Essential for gas laws, thermodynamics.
Common Use Cases
🌍 Travel & Weather
Convert weather forecasts when traveling internationally. USA uses Fahrenheit, rest of world uses Celsius. Understand local temperature reports, pack appropriate clothing. Hotel thermostats, oven temperatures differ by country. Essential for international travel, expat living, and understanding global weather news.
👨🍳 Cooking & Baking
Convert oven temperatures for recipes from different countries. USA recipes use Fahrenheit, European use Celsius. Baking precision critical—wrong temperature ruins results. 180°C = 356°F common baking temp. Meat doneness, candy making, bread proofing all temperature-dependent. Essential for following international recipes.
🔬 Science & Education
Convert temperatures for physics, chemistry experiments, homework. Kelvin required for gas laws, thermodynamics. Scientific papers use Celsius/Kelvin. Students need conversions for problem-solving. Absolute zero, phase transitions, reaction rates all temperature-dependent. Critical for STEM education and research.
🏥 Medical & Health
Convert body temperature readings. Normal body temperature 37°C = 98.6°F. Digital thermometers switch between scales. Fever thresholds differ by scale—38°C = 100.4°F is fever. Medical literature uses Celsius internationally, Fahrenheit in USA. Understanding vital signs internationally essential.
🏭 Engineering & Industry
Convert temperatures for manufacturing processes, material specifications, quality control. Metal melting points, plastic molding temperatures, chemical processes all temperature-critical. International standards may use different scales. HVAC systems, refrigeration, industrial ovens require precise temperature control and conversion.
🏠 Home & Daily Life
Convert thermostat settings, understand appliance manuals, follow care instructions. Pool/spa temperature preferences, aquarium heaters, wine storage all temperature-specific. Smart home devices may display different units. Understanding temperature conversions improves comfort, efficiency, and proper equipment use.