Temperature Converter

Convert temperatures between Celsius, Fahrenheit, Kelvin and Rankine scales using exact mathematical formulae with four decimal precision.

Enter a temperature value

Type the numeric temperature and select the source scale. The converter simultaneously calculates equivalent values in all four scales.

Understand the four scales

Celsius is the international standard, Fahrenheit is common in the US, Kelvin is the SI thermodynamic unit, and Rankine is the Fahrenheit-based absolute scale.

Validate against absolute zero

Temperatures below absolute zero (-273.15°C, -459.67°F, 0 K, 0°R) are physically impossible. The converter rejects such inputs for Kelvin and Rankine.

Use exact formulae

Conversions use the precise mathematical relationships: °F = °C × 9/5 + 32, K = °C + 273.15, °R = K × 9/5.

Temperature Converter FAQs

Absolute zero is -459.67°F, equivalent to -273.15°C, 0 K and 0°R.
Yes. The freezing point of water at standard atmospheric pressure is exactly 0°C or 32°F.