Temperature

How it is calculated

Multiplying is not enough: the scales have different zeros. °F = °C × 9/5 + 32, °C = (°F − 32) × 5/9, K = °C + 273.15 and °R = °F + 459.67.

Worked by hand: an oven at 180 °C → 180 × 1.8 + 32 = 356 °F. References: water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F) at sea level; −40 °C = −40 °F.

Keep in mind

• A temperature difference has no offset: a rise of 10 °C equals a rise of 18 °F or 10 K. This tool converts temperatures, not differences.
• Water boils at a lower temperature at altitude, about 1 °C less for every 300 m: at 3000 m it boils at about 90 °C, which lengthens cooking and sterilisation times.