Temperature comparison
Celsius vs Fahrenheit: Differences, Formulas & Chart
Celsius and Fahrenheit measure the same physical quantity but use different zero points and degree sizes. Celsius places water's familiar freezing and boiling reference points near 0° and 100°; Fahrenheit places them at 32° and 212°. Neither scale is inherently more accurate—the right choice depends on the audience, place and purpose.
Last reviewed: September 9, 2026 · Tested and edited by WOW Webtools
The short answer
Use Celsius for science, metric contexts and most international weather reports. Use Fahrenheit for everyday temperatures aimed primarily at a United States audience. Convert with °F = (°C × 9/5) + 32 or °C = (°F − 32) × 5/9.
Convert any temperature →Side-by-side comparison
| Question | Celsius | Fahrenheit |
|---|---|---|
| Water freezes | 0°C | 32°F |
| Water boils* | 100°C | 212°F |
| Degree size | 1°C = 1.8°F | 1°F = 5/9°C |
| Common use | Science and most countries | Everyday use mainly in the US |
| Absolute zero | −273.15°C | −459.67°F |
*Freezing and boiling vary with pressure and conditions. These are familiar standard-atmosphere reference values.
The exact Celsius to Fahrenheit formula
Multiply the Celsius value by 9/5, then add 32. For 20°C: (20 × 9/5) + 32 = 68°F. The multiplication changes the degree size; adding 32 aligns the scales' different zero points. To reverse it, subtract 32 first and multiply by 5/9: (68 − 32) × 5/9 = 20°C. Parentheses matter.
Useful temperature reference points
A cool room around 20°C is 68°F. A warm day at 30°C is 86°F. Water freezes near 0°C/32°F and boils near 100°C/212°F at standard atmospheric pressure. A quick weather estimate is to double Celsius and add 30, but use the exact formula for cooking, science or documentation.
Why the scales feel different
A Fahrenheit degree is smaller, so a 10°F change equals about 5.56°C. Celsius offers an intuitive 0-to-100 interval between familiar water reference points and aligns with metric practice. The scales meet at −40: −40°C equals −40°F.
Which scale should you publish?
Match your audience and add the alternative in parentheses when readers may use both. Travel, health and international content often benefits from both scales. Do not add more decimal places than the original measurement supports: converting 20°C to 68.000°F invents precision that was never measured.
Try the calculation yourself
Use the working tool with your own values, then return to this guide to interpret the result and check the assumptions.
Convert any temperature →Frequently asked questions
Is Celsius more accurate than Fahrenheit?
No. Accuracy depends on the instrument, calibration and method, not the labeling scale.
Where are Celsius and Fahrenheit equal?
At −40 degrees: −40°C = −40°F.
How can I estimate Celsius to Fahrenheit?
Double Celsius and add 30 for a rough weather estimate; use the exact formula when accuracy matters.
Is 20°C hot or cold?
20°C is 68°F and generally mild, although comfort also depends on humidity, wind, activity and personal preference.
Methodology and sources
Checked against the primary references below. Examples are original and explain the comparison; they do not replace controlling standards, contracts or professional advice.