0°C to 32°F
(0 × 9/5) + 32 = 32°F
water freezes
Celsius to Fahrenheit Formula
°F = (°C × 9/5) + 32
Conversion factors follow SI relationships published by BIPM and NIST, where those standards apply.
Equivalent: °F = (°C × 1.8) + 32. Reverse: °C = (°F − 32) × 5/9. Kelvin: K = °C + 273.15.
Celsius to Fahrenheit Converter
Quick Answer
1 °C = 33.8 °F
Formula: Fahrenheit = (Celsius x 9/5) + 32
Formula verifiedLive calculation
To (Fahrenheit)
°F
Quick values
How to Convert Celsius to Fahrenheit
Use the exact formula °F = (°C × 9/5) + 32.
- Multiply the Celsius temperature by 9.
- Divide the result by 5.
- Add 32 and round only at the end.
Worked conversion examples
20°C to 68°F
(20 × 9/5) + 32 = 68°F
room temperature
25°C to 77°F
(25 × 9/5) + 32 = 77°F
warm day
37°C to 98.6°F
(37 × 9/5) + 32 = 98.6°F
body-temperature reference
180°C to 356°F
(180 × 9/5) + 32 = 356°F
common oven setting
−40°C to −40°F
(−40 × 9/5) + 32 = −40°F
the scales are equal
Mental shortcut: For a quick estimate, double the Celsius value and add 30. Use the exact formula when accuracy matters.
View the complete Celsius to Fahrenheit chart →Accuracy, standards, and review
Values use the exact temperature-scale relationship in the shared conversion engine. Intermediate values are not rounded; displayed answers are rounded only for readability.
Reviewed by the All Unit Conversions Editorial Team. Updated .
Sources
- NIST SI units of temperature — Kelvin is the SI base unit of thermodynamic temperature; degree Celsius is an SI derived unit with the same magnitude.
- BIPM SI Brochure — kelvin and degree Celsius — Kelvin is the SI base unit of thermodynamic temperature; the degree Celsius is an SI derived unit with the same magnitude.
- BIPM SI base units — Official SI base-unit definitions used to derive conversion factors.
Worked examples
- 0 °C freezing point: (0 × 9/5) + 32 = 32 °F
- 20 °C room temperature: (20 × 9/5) + 32 = 68 °F
- 37 °C body-temperature reference: (37 × 9/5) + 32 = 98.6 °F
What is celsius to fahrenheit?
Fahrenheit equals Celsius times 9/5 plus 32. Degree Celsius has the same magnitude as the kelvin; Fahrenheit is the common US customary scale.
Formula°F = (°C × 9/5) + 32
Key conversions
- 0 °C = 32 °F (water freezes)
- 100 °C = 212 °F (water boils)
- −40 °C = −40 °F (scales equal)
How do you convert Celsius to Fahrenheit?
Fahrenheit equals Celsius times 9/5 plus 32: °F = (°C × 9/5) + 32. The two scales share one linear relationship with different zeros and degree sizes. Water freezes at 0 °C / 32 °F and boils at 100 °C / 212 °F at standard atmospheric pressure. The scales are equal at −40.
Degree Celsius is an SI derived unit with the same magnitude as the kelvin (BIPM). Fahrenheit is a US customary scale. This calculator applies the exact 9/5 ratio; it does not approximate with “double and add 30,” which is only a mental estimate.
Category hub: Temperature Conversion · Conversion charts · Conversion formulas
Fixed points on both scales
Use the exact formula for lab, medical, and oven work. The “double and add 30” shortcut is about 2 °F high near room temperature and should stay a weather-of-the-day estimate.
| Celsius (°C) | Fahrenheit (°F) | Common reference |
|---|---|---|
| -40 | -40 | Equal-temperature point |
| 0 | 32 | Water freezing (1 atm) |
| 20 | 68 | Typical room temperature |
| 37 | 98.6 | Historical body-temperature reference |
| 100 | 212 | Water boiling (1 atm) |
| 180 | 356 | Common baking oven setting |
Common Celsius to Fahrenheit reference points
Celsius to Fahrenheit Conversion Table
Everyday temperatures converted with °F = (°C × 9/5) + 32
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| -40 °C | -40 °F |
| -18 °C | -0.4 °F |
| 0 °C | 32 °F |
| 10 °C | 50 °F |
| 20 °C | 68 °F |
| 25 °C | 77 °F |
| 30 °C | 86 °F |
| 37 °C | 98.6 °F |
| 100 °C | 212 °F |
| 180 °C | 356 °F |
Freezing and boiling points are at standard atmospheric pressure. Oven and body-temperature rows are conventional references, not medical advice.
Browse all conversion charts → · Browse conversion formulas →
Practical use cases for Celsius to Fahrenheit
Weather and Climate
Understanding weather forecasts and climate data from different countries. Most countries use Celsius, while the US uses Fahrenheit, requiring conversions for international weather information.
Cooking and Food Safety
Following recipes and ensuring proper cooking temperatures. Oven temperatures and cooking instructions vary by country, requiring conversions between Celsius and Fahrenheit.
Medical and Health
Monitoring body temperature and understanding medical information. Different countries use different temperature scales for medical measurements, requiring conversions for international health records.
Industrial Processes
Controlling manufacturing temperatures and process parameters. International industrial standards may use different temperature scales, requiring conversions for global operations.
Scientific Research
Conducting experiments and analyzing data that may use different temperature scales. Scientific literature and international collaborations require accurate temperature conversions.
HVAC and Building Systems
Setting and monitoring heating and cooling systems. Building codes and equipment specifications from different countries use different temperature scales, requiring conversions.
Celsius to Fahrenheit FAQs
Common questions about converting celsius to fahrenheit.
What is the exact Celsius to Fahrenheit formula?
Multiply the Celsius value by 9/5 (or 1.8) and add 32. Example: 20 × 9/5 + 32 = 68 °F. The reverse is °C = (°F − 32) × 5/9. Both ratios are exact; round only the displayed result.
What temperature is the same in Celsius and Fahrenheit?
−40. Setting C = F in °F = (C × 9/5) + 32 gives C = −40. That is a scale-crossing identity, not a physical fixed point of water.
Is 37 °C exactly 98.6 °F?
37 × 9/5 + 32 = 98.6 °F exactly with one decimal. Clinical body temperature is a range, not a single value; 37 °C is the conventional reference this page converts, not a diagnosis.
Why does the US still use Fahrenheit?
Everyday US weather, cooking, and HVAC copy kept Fahrenheit after most countries adopted Celsius with the metric system. Science, medicine, and SI work use Celsius or kelvin. Convert with 9/5, not with a rounded 2 °F-per-°C guess.
How do I estimate Celsius to Fahrenheit without a calculator?
Double the Celsius value and add 30 for a weather estimate (20 °C → 70 °F vs the exact 68 °F). For anything that needs a degree or better — ovens, labs, fever checks — use °F = (°C × 9/5) + 32.
Charts and printable PDF
Use the matching celsius / fahrenheit chart when you need a printable table or offline reference.
Embed this converter
Add this Celsius to Fahrenheit calculator to another site with one async script or a lazy iframe. Keep the Powered by AllUnitConversions attribution so referrals stay canonical.
Docs: /embed?pair=c-to-f · iframe source: /widget