Why does Kelvin not use the degree symbol?

Kelvin is an absolute temperature scale, not a "degree" scale. You write "273.15 K", not "273.15°K". Celsius and Fahrenheit use the degree symbol because their scales are relative to chosen reference points.

What is absolute zero in each scale?

Absolute zero — the lowest possible temperature — is 0 K, −273.15°C, or −459.67°F.

Temperature Converter

Convert between Celsius, Fahrenheit, and Kelvin instantly.

Inputs

Value to convert*

From unit*

To unit*

Enter your values to see results instantly.

How this works

Formula

°F = °C × 9/5 + 32 · °C = (°F − 32) × 5/9 · K = °C + 273.15

Temperature measures how hot or cold something is. The three common scales are Celsius (used worldwide), Fahrenheit (used in the US), and Kelvin (used in science).

Celsius sets water's freezing point at 0° and boiling point at 100°. Fahrenheit sets them at 32° and 212°. Kelvin uses the same scale as Celsius but starts at absolute zero (−273.15°C), so it has no negative values.

To convert, first convert to Celsius as an intermediate, then to your target scale. The formulas use exact fractions (9/5 and 5/9) for precision.

Worked example

100°C to Fahrenheit

Value100

FromCelsius

ToFahrenheit

Result

100 × 9/5 + 32 = 180 + 32 = 212°F (the boiling point of water).

Frequently asked questions

Related calculators

Length Converter