Temperature Converter

Convert Celsius, Fahrenheit and Kelvin with absolute-zero validation.

Temperature Converter

Worked example result
Converted temperature32.0000
Summary0 °C = 32 °F

Water freezes at 0 °C, which is exactly 32 °F (and 273.15 K).

Convert between the three temperature scales. Celsius and Fahrenheit are related by °F = °C × 9/5 + 32, and Kelvin is simply °C + 273.15 — the kelvin uses the same degree size as Celsius but starts at absolute zero.

The converter rejects temperatures below absolute zero (−273.15 °C, −459.67 °F, 0 K), the coldest temperature physically possible.

The formula

°F = °C × 9/5 + 32 · K = °C + 273.15

Worked example

Water freezes at 0 °C, which is exactly 32 °F (and 273.15 K).

The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.

Frequently asked questions

Where are Celsius and Fahrenheit equal?

At −40: −40 °C = −40 °F. It is the only point where the two scales meet.

How do I convert Fahrenheit to Celsius in my head?

Subtract 32, then multiply by 5/9. For a quick weather estimate, subtract 30 and halve — 70 °F ≈ 20 °C (the exact answer is 21.1 °C).

Why does Kelvin have no degree symbol?

The kelvin is an SI base unit of absolute temperature, so it is written plain: 300 K, not 300 °K. Zero kelvin is absolute zero.

Category: Unit Conversions calculators