CCalcy .IN
🌡️
Converters

Temperature Converter

Convert between Celsius, Fahrenheit and Kelvin instantly, with the exact formula used shown below.

What this calculator does

Temperature is measured on three common scales, and this calculator converts a value from any one of them to any other: Celsius (used in most of the world for everyday and scientific use), Fahrenheit (used mainly in the US for everyday temperature), and Kelvin (the SI scientific unit, where 0 K is absolute zero).

The formulas

  • Celsius to Fahrenheit: °F = (°C × 9/5) + 32
  • Fahrenheit to Celsius: °C = (°F − 32) × 5/9
  • Celsius to Kelvin: K = °C + 273.15
  • Kelvin to Celsius: °C = K − 273.15

Any Fahrenheit-Kelvin conversion is done by routing through Celsius internally, since that's the simplest path between the three scales.

Worked example

Water boils at 100°C. Converting to Fahrenheit: (100 × 9/5) + 32 = 180 + 32 = 212°F. Converting the same 100°C to Kelvin: 100 + 273.15 = 373.15 K. All three numbers describe the exact same physical temperature — boiling water at standard atmospheric pressure — just on different scales.

Reference points worth remembering

  • Water freezes at 0°C / 32°F / 273.15 K
  • Water boils at 100°C / 212°F / 373.15 K
  • Normal human body temperature is roughly 37°C / 98.6°F
  • Absolute zero (the coldest theoretically possible temperature) is 0 K / −273.15°C / −459.67°F

Common mistakes

The most common error is forgetting the +32 offset when converting to or from Fahrenheit — unlike the Celsius-Kelvin relationship (a pure offset with no scaling), Celsius and Fahrenheit differ in both scale and offset, so you can't just add or subtract a fixed number.

Frequently asked questions

Celsius and Kelvin share the same size of degree, just with a different zero point (a pure offset of 273.15), so converting between them is simple addition or subtraction. Fahrenheit uses a different degree size entirely, so converting to or from it also requires multiplying or dividing by 9/5.

0 Kelvin, equal to −273.15°C or −459.67°F — the theoretical lowest possible temperature, where classical thermal motion is at a minimum.

The US is the main country still using Fahrenheit for everyday weather and temperature; most of the rest of the world uses Celsius day-to-day, while Kelvin is used almost universally in scientific contexts.

No — Kelvin starts at absolute zero and cannot go below 0 K, unlike Celsius and Fahrenheit, which both have negative ranges.