Math Playground
Measurement

Temperature

Celsius ↔ Fahrenheit. Drag the thermometer to flip the scale.

Three scales: Celsius (°C, used almost everywhere), Fahrenheit (°F, mostly the US), and Kelvin (K, science). They measure the same thing, just from different starting points.

Type a value, pick units
68

20 °C = 68 °F

Three scales, same heat

  • Celsius (°C) — water freezes at 0°, boils at 100°. Used almost everywhere.
  • Fahrenheit (°F) — water freezes at 32°, boils at 212°. Mainly the US.
  • Kelvin (K) — starts at absolute zero (−273.15 °C). Used in science; no negatives.
  • 20 °C ≈ 68 °F — a comfortable room.
°C to °F
Your turn

Body temperature is about 37 °C. What's that in °F?

The Celsius and Fahrenheit scales cross at exactly −40°: −40 °C = −40 °F.

C to F
F to C
C to K
Try it

100 °C in °F?

100 × 9/5 + 32 = 180 + 32 = 212 °F. (Boiling water.)

Try it

−40 °C in °F?

−40 × 9/5 + 32 = −72 + 32 = −40 °F. The two scales meet at −40°.