Temperature Converter
Convert between different temperature scales including Celsius, Fahrenheit, Kelvin, and Rankine with precise calculations.
Temperature Conversion Calculator
Common Temperature Conversions
Temperature Scales Reference
Celsius
Water freezes at 0°C and boils at 100°C
- • Freezing: 0°C
- • Boiling: 100°C
- • Body temp: 37°C
Fahrenheit
Water freezes at 32°F and boils at 212°F
- • Freezing: 32°F
- • Boiling: 212°F
- • Body temp: 98.6°F
Kelvin
Absolute temperature scale starting at absolute zero
- • Absolute zero: 0K
- • Freezing: 273.15K
- • Boiling: 373.15K
Rankine
Absolute temperature scale using Fahrenheit degrees
- • Absolute zero: 0°R
- • Freezing: 491.67°R
- • Boiling: 671.67°R
Conversion Formulas
From Celsius
- °F = (°C × 9/5) + 32
- K = °C + 273.15
- °R = (°C + 273.15) × 9/5
To Celsius
- °C = (°F - 32) × 5/9
- °C = K - 273.15
- °C = (°R × 5/9) - 273.15
Understanding Temperature Conversions
Temperature is different from most conversions because the scales do not share a zero point. Celsius and Fahrenheit have different freezing points (0 °C = 32 °F), so you cannot simply multiply by a factor, you must apply a formula that both scales and shifts the value.
To convert Celsius to Fahrenheit: °F = (°C × 9/5) + 32. To convert Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Kelvin, the SI base unit, starts at absolute zero, so K = °C + 273.15. The Rankine scale does the same for Fahrenheit. These offsets are why −40 °C and −40 °F are the one temperature where the two scales meet.
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 (1.8) and add 32. For example, 20 °C × 1.8 + 32 = 68 °F.
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, (98.6 − 32) × 5/9 = 37 °C.
What is 0 Kelvin in Celsius?
0 Kelvin is absolute zero, which equals −273.15 °C, the lowest possible temperature.
At what temperature are Celsius and Fahrenheit equal?
They are equal at −40 degrees: −40 °C is exactly −40 °F.