Convert Celsius to Fahrenheit
Convert degrees celsius to degrees fahrenheit instantly. °F = (°C × 9/5) + 32 — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Fahrenheit to Celsius converter for the reverse conversion.
Units explained
Celsius
The degree Celsius (°C) is the SI's everyday temperature unit. One degree Celsius is exactly the same size as one kelvin, with the zero point shifted so that 0 °C = 273.15 K. Water freezes near 0 °C and boils near 100 °C at standard atmospheric pressure.
Named for Swedish astronomer Anders Celsius, who in 1742 proposed a 100-degree scale between the boiling and freezing points of water. His original scale ran in reverse (0 at boiling, 100 at freezing); it was inverted to the modern direction shortly after his death.
The world's standard everyday temperature scale, used in nearly every country — including throughout India — for weather forecasts, cooking, medicine, science classrooms, and industry.
Devised by Anders Celsius at Uppsala University, Sweden, in 1742; the inverted modern form was in use by 1745, and the name 'degree Celsius' replaced 'degree centigrade' internationally at the 9th CGPM in 1948.
Fahrenheit
The degree Fahrenheit (°F) sets the freezing point of water at 32 °F and the boiling point at 212 °F, dividing the interval into 180 equal degrees. One degree Fahrenheit is exactly 5/9 the size of a kelvin, and °F = °C × 9/5 + 32 exactly.
Created by German-born physicist Daniel Gabriel Fahrenheit, inventor of the reliable mercury-in-glass thermometer. His zero point was the temperature of an ice-and-salt brine mixture, and his original upper fixed point sat near human body temperature.
The official everyday scale of the United States and a handful of other countries. In India, clinical thermometers and fever readings are still very commonly quoted in Fahrenheit (a '102-degree fever'), which keeps °F to °C conversion a daily need.
Introduced by Daniel Gabriel Fahrenheit in 1724 in Amsterdam, building directly on Ole Rømer's earlier scale, which Fahrenheit had studied during a 1708 visit to Copenhagen.
Celsius to Fahrenheit conversion formula
The exact relationship between degrees celsius and degrees fahrenheit:
To convert degrees celsius to degrees fahrenheit, multiply the value by 9/5, then add 32. To reverse, subtract 32 from the value, then multiply by 5/9.
Reference anchors: water freezes at 0 °C = 32 °F and boils at 100 °C = 212 °F (at standard atmospheric pressure).
How to use this converter
Type a value into the calculator. The result in degrees fahrenheit updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Fahrenheit to Celsius converter for the reverse direction.
Step-by-step: convert degrees celsius to degrees fahrenheit
- Write down the temperature in degrees celsius (°C).
- Multiply the value by 9/5, then add 32.
- The result is the same temperature expressed in degrees fahrenheit (°F).
- To reverse, subtract 32 from the value, then multiply by 5/9 — or open the Fahrenheit to Celsius converter.
Worked examples
Example 1 — Convert 37 °C to °F (human body temperature):
(37 × 9/5) + 32 = 98.6 °F
Example 2 — Convert 100 °C to °F (the boiling point of water):
(100 × 9/5) + 32 = 212 °F
Celsius to Fahrenheit conversion table
Physically meaningful reference temperatures, from absolute zero to the surface of the Sun, converted from degrees celsius to degrees fahrenheit:
| Celsius [°C] | Fahrenheit [°F] | Reference point |
|---|---|---|
| -273.15 | -459.67 | Absolute zero |
| -40 | -40 | Where Celsius and Fahrenheit coincide (−40°) |
| -17.7777777778 | 0 | Zero Fahrenheit (0 °F) |
| 0 | 32 | Water freezes (0 °C / 32 °F) |
| 0.01 | 32.018 | Triple point of water |
| 10 | 50 | Cool day (10 °C / 50 °F) |
| 20 | 68 | Room temperature (20 °C / 68 °F) |
| 25 | 77 | Standard laboratory temperature (25 °C) |
| 30 | 86 | Hot day (30 °C / 86 °F) |
| 37 | 98.6 | Human body temperature (37 °C / 98.6 °F) |
| 40 | 104 | Heat-wave day (40 °C / 104 °F) |
| 50 | 122 | Hot tap water (50 °C / 122 °F) |
| 100 | 212 | Water boils (100 °C / 212 °F) |
| 180 | 356 | Moderate baking oven (180 °C / 356 °F) |
| 5504.85 | 9940.73 | Surface of the Sun (≈5,505 °C) |
Frequently asked questions
What is 37 °C in °F?
How do I convert degrees celsius to degrees fahrenheit?
How do I convert degrees fahrenheit back to degrees celsius?
At what temperature do the Celsius and Fahrenheit scales read the same number?
Can a temperature be below absolute zero?
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Sources & references
Conversion relationship (°F = (°C × 9/5) + 32) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- BIPM — International Temperature Scale of 1990 (ITS-90)
The internationally agreed practical temperature scale, defining fixed points (including the triple point of water at 273.16 K) and interpolation instruments used by national metrology institutes for thermometer calibration worldwide.
- CODATA Internationally Recommended Values of the Fundamental Physical Constants
Committee on Data of the International Science Council; authoritative source for the masses of fundamental particles (electron, proton, neutron) and the atomic mass constant.