Which is the correct formula to convert Fahrenheit to Celsius?

• A. (F − 32) × 5/9
• B. F × 9/5 + 32
• C. (F − 32) × 9/5
• D. F − 32 × 5/9

Answer: (A)

Converting Fahrenheit to Celsius relies on aligning the two temperature scales and then adjusting for the difference in how big each step is. First, subtract 32 to shift the freezing point from 32 °F to 0 °C. Then multiply by 5/9 to convert the unit size from Fahrenheit to Celsius. This two-step process gives the correct formula: (F − 32) × 5/9. For example, 212 °F (the boiling point) becomes (212 − 32) × 5/9 = 100 °C, and 32 °F becomes (32 − 32) × 5/9 = 0 °C, as expected.

The other options don’t fit: the Fahrenheit-to-Celsius reverse is F = C × 9/5 + 32, not applicable here; using 9/5 after subtracting 32 overestimates the result; and the version without proper parentheses would subtract 32 × 5/9 from F, which is not the intended sequence.