Celsius to Fahrenheit Converter
Turn Celsius into Fahrenheit for recipes, forecasts, classroom work, and quick reference.
How to use this Celsius to Fahrenheit converter
- Enter Celsius
Type the temperature into the Celsius field.
- Read the result
The equivalent value in Fahrenheit appears instantly.
- Double-check with the shortcut
For a rough estimate, double the Celsius value and add 30.
How this Celsius to Fahrenheit converter works
This page converts Celsius to Fahrenheit using the exact linear formula that connects the two scales. It is especially useful for cooking, weather interpretation, and everyday temperature conversions across regions using different systems.
°F = °C × 9/5 + 32 20 °C × 9/5 + 32 = 68 °F.
A recipe says to set the oven to 180 °C. In Fahrenheit: 180 × 9/5 + 32 = 356 °F — round to 350 °F on a standard oven dial.
- ✓ All three conversions are exact linear transformations — no rounding or approximation is applied to the formulas themselves.
- ✓ Kelvin values below 0 are physically impossible (absolute zero is 0 K = −273.15 °C); the calculator will still compute them but they have no physical meaning.
- ✓ The Celsius scale used here is the modern definition tied to the kelvin via the 2019 SI redefinition, where one degree Celsius equals exactly one kelvin.
- ✓ Results are displayed rounded to two decimal places; internal arithmetic uses full floating-point precision.
- The formula °F = °C × 9/5 + 32 is exact by definition — memorizing it and the inverse covers the vast majority of everyday temperature conversions.
- At −40°, Celsius and Fahrenheit intersect: −40 °C = −40 °F. This is a useful mental anchor for checking your conversions.
- Kelvin is the SI base unit for thermodynamic temperature and is used in scientific contexts where ratios matter (e.g. gas laws, blackbody radiation). It has no degree symbol.
- For cooking and weather, Celsius-to-Fahrenheit is the most common conversion; for physics and chemistry, Celsius-to-Kelvin dominates.
- National Institute of Standards and Technology (NIST) — Guide for the Use of the International System of Units
- Bureau International des Poids et Mesures (BIPM) — The International System of Units (SI), 9th edition, 2019
Celsius and Fahrenheit in everyday life
Celsius is the default temperature scale in most of the world, used for weather forecasts, cooking, science, and medicine. Fahrenheit is still standard in the United States and a few other territories for weather and oven settings. The two scales share one crossover point at −40°, where both read the same value. For comfortable room temperature, 20–22 °C corresponds to 68–72 °F. For cooking, common oven settings range from 150 °C (300 °F) to 230 °C (450 °F). Remembering a few anchor points like these makes it easy to estimate conversions without a calculator.
Celsius to Fahrenheit converter FAQs
What is 0 °C in Fahrenheit?
0 °C equals 32 °F, which is the freezing point of water at standard pressure.
Is there a quick way to estimate Celsius to Fahrenheit in my head?
Double the Celsius value and add 30. For example, 25 °C is roughly 2 × 25 + 30 = 80 °F. The exact answer is 77 °F, so the shortcut is close enough for everyday use.
Why does the formula multiply by 9/5 and then add 32?
The 9/5 factor adjusts for the different degree sizes (a Fahrenheit degree is smaller), and adding 32 shifts the scale so that the freezing point of water lines up correctly.