Weather
The gap between the scales is widest in the range people care about. 20 °C is a pleasant 68 °F, 30 °C is a hot 86 °F, and 35 °C is 95 °F — the point where heat advisories start in both systems.
Temperature
Convert celsius to fahrenheit
1 celsius equals 33.8 fahrenheit. Enter a value below to convert instantly.
Celsius to Fahrenheit is the one everyday conversion that cannot be done by multiplying alone. The two scales have different zero points and different degree sizes, so the formula needs both a ratio and an offset: multiply by 9/5, then add 32.
Need the other direction? Convert fahrenheit to celsius →
Formula
°F = (°C × 9/5) + 32
Not a simple multiplication. These scales have different zero points, so the conversion applies an offset as well as a ratio.
Step by step
- Start with 1 °C.
- Apply the Celsius-to-Fahrenheit formula.
- The result is 33.8 °F.
Celsius to Fahrenheit conversion table
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| -40 | -40 |
| -20 | -4 |
| 0 | 32 |
| 10 | 50 |
| 20 | 68 |
| 32 | 89.6 |
| 37 | 98.6 |
| 50 | 122 |
| 98.6 | 209.48 |
| 100 | 212 |
Where celsius and fahrenheit are used together
Oven temperatures
Recipes cross borders constantly and ovens do not. 180 °C is 356 °F, which US recipes round to 350 °F; 200 °C is 392 °F, rounded to 400 °F. Those roundings are why a converted baking time sometimes needs a few minutes' adjustment.
Body temperature
Normal body temperature is about 37 °C or 98.6 °F, and the fever threshold usually quoted is 38 °C or 100.4 °F. The 98.6 figure is itself a conversion artefact — it is 37 °C converted to one decimal place, which implies far more precision than the original measurement had.
Refrigeration and freezing
A fridge should sit at or below 4 °C (39 °F) and a freezer at −18 °C (0 °F). The freezer figure is a good example of a round number in one scale converting to a round number in the other, which is why both are quoted as standards.
Everyday celsius worth knowing
Values people actually look up, with the reason each one comes up. Every figure is calculated with the same engine as the converter above.
| Celsius (°C) | Fahrenheit (°F) | What it is |
|---|---|---|
| -40 | -40 | Where the two scales meet |
| -18 | -0.4 | Standard freezer temperature |
| 0 | 32 | Water freezes |
| 4 | 39.2 | Recommended fridge temperature |
| 20 | 68 | Room temperature |
| 37 | 98.6 | Normal body temperature |
| 100 | 212 | Water boils at sea level |
| 180 | 356 | A common baking temperature |
How these two units are defined
Celsius places 0 at the freezing point of water and 100 at its boiling point at standard pressure. Fahrenheit places those same two points at 32 and 212, so 180 Fahrenheit degrees span the same interval as 100 Celsius degrees — a Fahrenheit degree is 5/9 the size of a Celsius one. Both are now formally defined against the kelvin: the Celsius scale is exactly the kelvin scale shifted by 273.15, and Fahrenheit is defined from Celsius. The two scales cross at −40, where both read the same number.
Rounding and precision
Because a Fahrenheit degree is smaller, a converted Celsius value gains apparent precision it does not have: 20 °C measured to the nearest degree becomes 68 °F, but the true value could be anywhere from 66.2 to 69.8 °F. Round converted temperatures back to a sensible precision — whole degrees for weather, one decimal for clinical readings, and the nearest 5 or 10 for ovens, which cannot hold better than that anyway.
Mistakes people make with this conversion
-
Adding 32 before multiplying
Going from Fahrenheit to Celsius, subtract 32 first. Doing it the other way turns 100 °F into 73.3 °C instead of 37.8 °C — an answer that is wrong by enough to matter and not obviously absurd.
-
Converting a temperature difference like a temperature
A 10 °C rise is an 18 °F rise, not 50 °F. Differences use only the 9/5 ratio, with no offset. The site has a separate temperature-interval converter for exactly this.
-
Trusting 98.6 °F as a precise normal
It is 37 °C converted to one decimal place. The underlying figure was never that precise, and normal body temperature varies by person and time of day.
Read more about these units
Sources for this page
- SI Brochure — The International System of Units (SI), 9th edition
- Special Publication 330 — The International System of Units (SI), 2019 Edition
Content on this page last reviewed 12 August 2026. Spotted an error? Report it — see also how these values are calculated.
Convert Celsius to other temperature units
1 °C expressed in every other temperature unit on this site.
- Celsius °C 1
- Fahrenheit °F 33.8
- Kelvin K 274.15
- Rankine °R 493.47
- Réaumur °Ré 0.8
- Delisle °De 148.5
- Newton Scale °N 0.33
- Rømer °Rø 8.025
About the celsius
The celsius (°C) is a Metric unit of temperature.
About the fahrenheit
The fahrenheit (°F) is a US unit of temperature.
Related conversions
Frequently asked questions
What is the formula for Celsius to Fahrenheit?
°F = (°C × 9/5) + 32. The 9/5 accounts for the different degree size and the 32 accounts for the different zero point; both steps are needed, in that order.
Is there a quick mental approximation?
Double the Celsius figure and add 30. For 20 °C that gives 70 against the true 68 — close enough for weather, and it drifts further apart the hotter it gets (at 40 °C it gives 110 against 104).
At what temperature are Celsius and Fahrenheit the same?
At −40. Setting °C = °F in the formula and solving gives exactly −40, the one point where the two scales read the same number.
How many fahrenheit are in a celsius?
One celsius equals 33.8 fahrenheit.
How do you convert celsius to fahrenheit?
°F = (°C × 9/5) + 32
What is 1 fahrenheit in celsius?
One fahrenheit equals -17.222222 celsius.
When would I convert celsius to fahrenheit?
This conversion is common when cooking, weather, medical readings, and science experiments.