Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin temperature scales instantly.
About Temperature Converter
A temperature converter transforms temperature readings between Celsius, Fahrenheit, and Kelvin scales. Each scale has different reference points: Celsius uses water's freezing (0°C) and boiling (100°C) points, Fahrenheit uses 32°F and 212°F for the same, and Kelvin starts at absolute zero (0 K, the theoretical minimum temperature). Temperature conversion is needed for cooking, weather interpretation, scientific work, medical applications, and international travel.
How to Use
Enter a temperature value and select the source scale. The converter instantly shows the equivalent temperature in all three major scales — Celsius, Fahrenheit, and Kelvin — so you get all conversions at once without needing to select a target unit. This makes it easy to compare temperatures across scales simultaneously.
Formula / Key Equations
The conversion formulas are: F = (C × 9/5) + 32, C = (F - 32) × 5/9, K = C + 273.15, and F = (K - 273.15) × 9/5 + 32. The relationship between Celsius and Kelvin is a simple offset of 273.15, while Fahrenheit involves both multiplication and addition.
Common Use Cases
Travelers use it to understand weather forecasts in different countries (US uses Fahrenheit, most others use Celsius). Scientists and engineers use Kelvin for thermodynamic calculations. Cooks convert oven temperatures between recipes from different regions. Medical professionals convert body temperature readings. HVAC technicians use it for system calibration.
Limitations
This converter supports Celsius, Fahrenheit, and Kelvin. It does not include Rankine (the absolute scale for Fahrenheit) or less common scales like Delisle or Newton. Results are displayed to 2 decimal places, which is sufficient for virtually all practical applications.
Frequently Asked Questions
What is normal body temperature in Fahrenheit?
Normal human body temperature is approximately 98.6°F (37°C). However, individual variations are common, and anything between 97°F and 99°F (36.1°C to 37.2°C) is generally considered normal.
Why does the US use Fahrenheit while most countries use Celsius?
The US adopted Fahrenheit early in its history and has maintained it for everyday use, while most of the world switched to Celsius as part of metrication. Fahrenheit offers finer granularity for weather (180 degrees between freezing and boiling vs 100 in Celsius), while Celsius aligns neatly with water's phase changes.
What is absolute zero?
Absolute zero is 0 Kelvin (-273.15°C or -459.67°F), the theoretical lowest possible temperature where all atomic motion ceases. It has never been achieved in practice, though scientists have gotten extremely close in laboratory settings.
How do I convert Celsius to Fahrenheit quickly?
A quick mental estimate: multiply the Celsius temperature by 2, add 30. For 20°C: 20×2+30 = 70°F (actual: 68°F). For precise conversion, use our calculator which applies the exact formula.
Is this temperature converter free to use?
Yes, it is completely free. No sign-up is required and all conversions are calculated locally in your browser.
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