Fahrenheit to Celsius Converter
Temperature · unit-converter
Convert Fahrenheit to Celsius with offset-aware formulas (not simple ratio scaling), step-by-step lines, and reference tables. Uses 273.15 for Celsius–Kelvin offsets, R = (9/5) × K for kelvin–rankine, and °F–R offset 459.67.
About Fahrenheit
Fahrenheit is common in the United States for weather and cooking. Water freezes at 32 °F and boils at 212 °F at standard pressure. Convert via Celsius or direct offset formulas.
About Celsius
Celsius is a metric scale where 0 °C is the freezing point of water and 100 °C is the boiling point at standard atmospheric pressure. It shares the same step size as kelvin (1 K = 1 °C interval).
How to convert Fahrenheit to Celsius
From Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Subtract 32 to remove the offset, then scale by 5/9.
Sanity check: 32 °F = 0 °C and 212 °F = 100 °C at 1 atm.
Unlike units with a single fixed ratio (meters to feet), absolute temperatures include an offset. Always use the full formula for this pair—do not “multiply only” by a scale factor unless you are computing a temperature difference (interval), where offsets cancel.
Examples
Example #1: Convert 32 f to Celsius
32F = 0.000000°C
→ 0 c
Example #2: Convert 68 f to Celsius
68F = 20.000000°C
→ 20 c
Summary
From Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Subtract 32 to remove the offset, then scale by 5/9.
Relationship context
Converting Fahrenheit to Celsius uses different zeros and step sizes. You cannot multiply by a single ratio alone for every pair—you first express the same physical temperature in an intermediate form (Celsius is used inside this tool), then map to Celsius. Unlike length or energy units, offsets matter for Celsius and Fahrenheit; kelvin and rankine are absolute scales linked by the exact factor 9/5.
Conversion tables
| Fahrenheit (f) | Celsius (c) |
|---|---|
| -40 | -40 |
| 0 | -17.7777777778 |
| 32 | 0 |
| 68 | 20 |
| Fahrenheit (f) | Celsius (c) |
|---|---|
| 86 | 30 |
| 100 | 37.7777777778 |
| 212 | 100 |