Convert Fahrenheit (°F) to Celsius (°C)
Category: Temperature
2.5 fahrenheit = -16.388889 celsius
High-precision rounding: 6 decimals
How to convert Fahrenheit to Celsius
We convert by pivoting through the SI base unit for Temperature and applying exact factors where applicable.
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Examples
Formula: °C = (°F − 32) × 5/9
Temperature conversions use exact affine formulas (ratio + offset).
Common mistakes
- Using only a ratio (×1.8 or ×0.555…) without adding/subtracting the offset (±32, +273.15).
- Rounding too early; convert first, then round to the desired precision.
About Temperature
Temperature scales combine ratios and offsets. Kelvin is absolute (no negative values), Celsius offsets Kelvin by 273.15, and Fahrenheit uses a different step and zero point. Because offsets exist, temperature conversions require both a factor and an addition/subtraction.
About Fahrenheit (°F)
Fahrenheit (°F)
Offset scale with 32 °F as water’s freezing point and 212 °F as boiling at 1 atm. Offers finer granularity per degree for everyday weather reporting in the US.
History: Proposed by Daniel G. Fahrenheit in the 18th century; based on calibration points available at the time.
About Celsius (°C)
Celsius (°C)
Offset scale with 0 °C at water’s freezing point and 100 °C at boiling (at 1 atm). Converts to Kelvin by adding 273.15. Widely used in daily weather and science.
History: Named for Anders Celsius (1740s). Redefined through absolute thermodynamic scales as metrology advanced.
Related conversions from fahrenheit
- fahrenheit → kelvin Kelvin (K)
- fahrenheit → rankine Rankine (°R)
Related conversions to celsius
- kelvin → celsius Kelvin (K)
- rankine → celsius Rankine (°R)