To convert a temperature from Fahrenheit (F) to Celsius (C), use this simple formula:
C = (F - 32) × 5/9
This formula works because the Fahrenheit scale starts at 32 degrees (freezing point of water) and has 180 degrees between freezing and boiling, while Celsius has 100 degrees between those points. Subtracting 32 adjusts the starting point, and multiplying by 5/9 scales it correctly.
Follow these steps for any conversion:
Example 1:Convert 98.6°F (normal body temperature).
98.6 - 32 = 66.6
66.6 × 5 = 333
333 / 9 = 37°C. So, 98.6°F is 37°C.
Example 2:Convert 212°F (boiling water).
212 - 32 = 180
180 × 5 = 900
900 / 9 = 100°C. Perfect match!
Quick tip:For a rough estimate, subtract 30 from Fahrenheit and divide by 2. For 98.6°F: 98.6 - 30 = 68.6, 68.6 / 2 = 34.3°C (close to 37°C—great for quick checks!).
DefinitionThe Fahrenheit scale measures temperature using degrees marked as °F. On this scale, water freezes at 32°F and boils at 212°F under standard conditions at sea level. It divides the range between freezing and boiling into 180 equal parts, making it finer than some other scales. Zero degrees was chosen based on the lowest temperature Fahrenheit could reliably create in his lab using a mix of ice, water, and salt.
History/OriginDaniel Gabriel Fahrenheit, a German physicist and engineer, created this scale in the early 1700s. He developed one of the first reliable thermometers using alcohol and later mercury, which allowed precise measurements. By 1724, he published his scale, setting human body temperature around 96°F for consistency with earlier ideas. His work improved weather tracking and scientific experiments during the Enlightenment era.
Current UseFahrenheit remains popular in the United States and a few other places like the Bahamas and Belize for daily life. People check weather in °F, set home thermostats, and follow cooking recipes using it. In science and industry, it's less common as most countries switched to metric systems, but Americans still use it for comfort in everyday tasks.
DefinitionThe Celsius scale, marked as °C, sets the freezing point of water at 0°C and the boiling point at 100°C at sea level standard pressure. This creates 100 equal divisions between these points, making calculations simple. It's part of the metric system, where temperature fits neatly with other measurements like length and mass.
History/OriginAnders Celsius, a Swedish astronomer, proposed the scale in 1742, originally with boiling at 0°C and freezing at 100°C. Scientists like Jean-Pierre Christin soon flipped it for practicality. Celsius used it for his studies of the Aurora Borealis and improved thermometer accuracy, helping standardize science across Europe during the 18th century.
Current UseCelsius is the global standard, used in nearly every country for weather, science, medicine, and education. It's the official scale in the International System of Units (SI). Even in the US, scientists and many products use °C, showing its dominance in international trade, aviation, and research.
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