Temperature Converter

What Is the Temperature Converter?

The Temperature Converter converts a temperature between Celsius (°C), Fahrenheit (°F), and Kelvin (K). Enter a value in one scale and it calculates the equivalent values in the other two scales using the standard conversion formulas. It is useful for weather, cooking, science homework, and travel between countries that use different scales.

Temperature scales have different zero points and degrees, so conversion is not a simple multiplication. Celsius and Fahrenheit are related by both a scale factor and an offset, and Kelvin is an absolute scale that starts at absolute zero.

How to Use the Temperature Converter

1. Enter the temperature value in the input box.
2. Select the unit you are converting from: Celsius, Fahrenheit, or Kelvin.
3. Select the unit you want to convert to.
4. Read the result. If a swap control is shown, use it to reverse the direction.
5. Copy the result if you need it in a document, recipe, or message.

Worked Example

Convert 100 °C to Fahrenheit:

°F = (°C × 9/5) + 32 = (100 × 9/5) + 32 = 180 + 32 = 212 °F. So 100 °C = 212 °F, the boiling point of water at standard atmospheric pressure.

Convert 32 °F to Celsius:

°C = (°F − 32) × 5/9 = (32 − 32) × 5/9 = 0 °C, the freezing point of water.

Convert 0 °C to Kelvin:

K = °C + 273.15 = 0 + 273.15 = 273.15 K.

Limitations

• Results are mathematical conversions only. They do not account for wind chill, heat index, altitude effects on boiling point, or thermometer calibration error.
• Kelvin cannot go below 0 K. A result below 0 K means the input is physically impossible or a value was entered incorrectly.
• Rounding can make repeated back-and-forth conversions differ by a small amount in the last decimal place.
• The tool does not measure temperature. Enter a value you read from a thermometer, forecast, recipe, or experiment.
• Very large or very small inputs may be shown in scientific notation depending on the tool display.

Frequently Asked Questions

What is the formula for Celsius to Fahrenheit?

°F = (°C × 9/5) + 32. For example, 20 °C = (20 × 9/5) + 32 = 68 °F.

What is the formula for Fahrenheit to Celsius?

°C = (°F − 32) × 5/9. For example, 68 °F = (68 − 32) × 5/9 = 20 °C.

What is absolute zero in each scale?

Absolute zero is 0 K, −273.15 °C, and −459.67 °F. No temperature can be lower than this.

Why do the US and most other countries use different scales?

The United States commonly uses Fahrenheit for weather and cooking, while most other countries use Celsius. Kelvin is used mainly in science. The converter bridges these uses without needing to memorise the formulas.