Unit Conversion

Convert numbers between two units quickly and precisely

Temperature Converter

Unit Conversion

Convert temperature units: Celsius, Fahrenheit, Kelvin, and Rankine

The temperature converter converts between Celsius (°C), the scale common in Europe, Fahrenheit (°F), the US standard, Kelvin (K), the SI unit of thermodynamics with its zero point at absolute zero, and Rankine (°R), an absolute temperature scale based on Fahrenheit.

Conversion formulas:

  • °F = °C * 1.8 + 32 – Celsius to Fahrenheit
  • K = °C + 273.15 – Celsius to Kelvin
  • °R = (°C + 273.15) * 1.8 – Celsius to Rankine
  • °C = (°F - 32) / 1.8 – Fahrenheit to Celsius

Key fixed points:

  • 0 °C = 32 °F = 273.15 K = 491.67 °R – freezing point of water at standard pressure
  • 100 °C = 212 °F = 373.15 K – boiling point of water at standard pressure
  • -40 °C = -40 °F – the only point where the Celsius and Fahrenheit scales intersect
  • 0 K = -273.15 °C – absolute zero, the lowest possible temperature

Applications:

  • Weather & travel planning: converting Fahrenheit figures from US weather reports
  • Cooking: converting oven temperatures from Fahrenheit-based recipes
  • Natural sciences: Kelvin as the basis for gas laws and reaction kinetics
  • Engineering: the Rankine scale in US thermodynamic calculations

The temperature converter reliably converts between all common scales – for science, engineering, and everyday international use. For temperature-dependent reaction rates, use our Arrhenius calculator.

Frequently asked questions about converting temperature

The formula is °F = °C * 1.8 + 32. For example, 20 °C equals exactly 68 °F. Conversely, °C = (°F - 32) / 1.8.

Kelvin is an absolute temperature scale whose zero point (0 K) is at absolute zero – the lowest possible temperature, at which particle motion is minimal. Since there can be no physically lower temperature, negative Kelvin values are not defined. 0 K equals -273.15 °C.

At -40 degrees, Celsius and Fahrenheit are identical: -40 °C = -40 °F. That's the only point where the two scales intersect.

Rankine (°R), like Kelvin, is an absolute temperature scale with its zero point at absolute zero, but it uses Fahrenheit-sized degree steps instead of Celsius-sized ones. It's mainly used in older US thermodynamic calculations. 0 K equals 0 °R, but the degree size differs.