Fahrenheit to Celsius

The formula is C = (F - 32) × 5/9. You subtract 32 from the Fahrenheit temperature, then multiply by 5/9 (or divide by 1.8). For example, 68°F becomes (68-32) × 5/9 = 20°C.

-40° is the only temperature where both scales meet. At -40°F and -40°C, you're reading the exact same temperature. This unusual coincidence happens because of how the two scales are offset and sized differently.

The US adopted Fahrenheit before the metric system was widely established in the 1700s. While most countries switched to Celsius as part of the metric system, the US kept Fahrenheit due to the high cost of changing infrastructure and public familiarity with the scale.

A rough estimate: subtract 30 and divide by 2. For 68°F, that's (68-30)/2 = 19°C, which is close to the exact 20°C. This works best for everyday temperatures between 30°F and 90°F.

Neither is more accurate—they're just different scales measuring the same thing. Celsius is based on water's freezing (0°) and boiling points (100°), while Fahrenheit uses a finer scale with 180 degrees between those points, giving more precision without decimals for everyday temps.