Temperature Converter

How it works

Bidirectional conversion using the exact scale formulas.

When this question comes up

Temperature is the one unit conversion where the scales do not share a zero, so multiplying by a factor is never enough. It comes up with oven settings, weather reports, fever thresholds and laboratory work — and the body-temperature case is where being one degree out actually matters.

Rules and limits

• The scales are not proportional: °F = °C × 9/5 + 32 and K = °C + 273.15.
• A value below 0 K is displayed as entered, but it has no physical meaning.

Worked example

100 °C = 212 °F · 0 °C = 273.15 K

Checking the result by hand

°F = °C × 9/5 + 32 and K = °C + 273.15. Two anchors make a result easy to sanity-check: 0 °C is 32 °F and 100 °C is 212 °F. A useful shortcut is to double the Celsius figure and add 30 for a rough Fahrenheit value — close enough for the weather, not for anything precise.

FAQ

Keep reading

• Celsius, Fahrenheit and Kelvin Without the ConfusionThe three temperature scales, the exact formulas, why a simple multiplier never works, and the anchors that let you check any result in your head.