Temperature Converter — Celsius, Fahrenheit & Kelvin

Double the Celsius and add 30. It's not exact, but it's close enough for everyday use. Example: 20°C → (20×2)+30 = 70°F (exact answer is 68°F). For more precision, use ×1.8 + 32.

37°C (98.6°F) is considered normal body temperature. Fever generally starts at 38°C (100.4°F) or above. At 39°C+ (102°F+) you're running a high fever. Above 40°C (104°F) you should seek medical attention.

-40°. That's the one point where both scales meet: -40°C = -40°F. It's an interesting curiosity, though you'll rarely encounter those temperatures unless you're in Siberia or certain parts of Canada in winter.

180°C = 356°F — most people round this to 350°F and it works fine for baking. Other common oven temperatures: 160°C = 320°F (slow/fan), 200°C = 392°F (hot), 220°C = 428°F (very hot).

Because Kelvin starts at absolute zero — the point where there's no thermal energy at all. This makes equations in thermodynamics and physics much cleaner. You can't have a "negative" Kelvin temperature, which avoids a lot of awkward minus signs in formulas.

Mostly inertia. Fahrenheit was widely adopted before the metric system existed, and the US never went through the metrication push that most other countries did in the 1970s. Science in the US uses Celsius and Kelvin — it's really just everyday life that sticks to Fahrenheit.

Absolute zero is 0 K = -273.15°C = -459.67°F. It's the theoretical lowest possible temperature — the point where molecular motion essentially stops. Scientists have gotten within a billionth of a degree of it, but it can't actually be reached.