Convert between Celsius, Fahrenheit, and Kelvin instantly.
Water freezes at 0°C, boils at 100°C
Water freezes at 32°F, boils at 212°F
Absolute zero is 0 K (−273.15°C)
Common reference points
The ToolBrainy Temperature Converter lets you instantly convert any temperature between Celsius (°C), Fahrenheit (°F), and Kelvin (K). Type a value in any field and all three update simultaneously, so you never have to press a button or wait for a result.
Whether you are cooking, checking the weather, studying thermodynamics, or reading a science paper, this tool handles every conversion in real time, right in your browser, with no data sent to any server.
Type any value into the Celsius, Fahrenheit, or Kelvin field. Decimals are fully supported.
The other two fields update automatically as you type, showing the equivalent temperature in every unit.
Click any common reference point (room temp, body temp, boiling point, etc.) to load it instantly.
Convert between Celsius, Fahrenheit, and Kelvin in one place.
Live results as you type, no calculate button needed.
Enter a value in any field and the others auto-fill instantly.
Runs entirely in your browser, nothing is sent to a server.
One-click presets for common temperatures like body temp and boiling point.
Results shown to four decimal places for scientific accuracy.
Convert oven temperatures between Celsius and Fahrenheit when following recipes from different countries.
Quickly understand foreign weather forecasts whether they are in Celsius or Fahrenheit.
Convert to Kelvin for thermodynamic calculations and scientific data interpretation.
Understand body temperature readings reported in different scales by different thermometers.
Convert temperature specs in technical datasheets and manuals between different unit systems.
Help students learn temperature scales and verify chemistry or physics homework answers.
Multiply the Celsius value by 9/5 and add 32. For example, 100°C = (100 × 9/5) + 32 = 212°F. This tool does the calculation automatically as you type.
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, 98.6°F − 32 = 66.6, then 66.6 × 5/9 = 37°C (normal body temperature).
Kelvin is the SI unit of temperature used in science. It starts at absolute zero (the coldest possible temperature). To convert Celsius to Kelvin, simply add 273.15. For example, 0°C = 273.15 K and 100°C = 373.15 K.
Absolute zero is the lowest possible temperature, defined as 0 Kelvin. It is equal to −273.15°C or −459.67°F. At this temperature, particles have minimum possible energy. It is a theoretical limit that cannot actually be reached in practice.
Yes. The tool uses the exact standard conversion formulas: °F = (°C × 9/5) + 32 and K = °C + 273.15. Results are shown to four decimal places for full precision.
Yes, negative values are fully supported. For example, you can enter −40 in either the Celsius or Fahrenheit field — that is the one temperature where both scales are equal (−40°C = −40°F).