98.6 °F = 37 °C, which is considered normal body temperature.

°C = (°F − 32) × 5 ÷ 9. For example, 101 °F = (101 − 32) × 5 ÷ 9 = 38.3 °C.

A temperature above 100.4 °F (38 °C) is usually considered a fever. If it is high or lasts 2–3 days, see a doctor.

Kelvin is the unit used in science. K = °C + 273.15.