Celsius (°C)
Used for weather, cooking, and everyday temperatures in most countries. Water freezes at 0 °C and boils near 100 °C at sea level.
Everyday converter
Temperature Converter
This temperature converter switches between Celsius, Fahrenheit, and Kelvin instantly in your browser. It applies °F = °C × 9/5 + 32 and refuses any value below absolute zero.
- Instant results
- Private & secureNo data is uploaded
- Works on all devices
Common temperature units
- Celsius (°C)Water freezes at 0 °C and boils at 100 °C at sea level
- Fahrenheit (°F)The same two points are 32 °F and 212 °F
- Kelvin (K)0 K is absolute zero, which is −273.15 °C
Conversion formula
Every conversion here uses the published factor, not a rounded one.
Example: Celsius to Fahrenheit
°F = °C × 9/5 + 32
Temperature scales have an offset as well as a ratio, so the 32 matters:
25 °C = 77 °F
Figures on this page are shown to seven significant digits. The converter keeps the full precision and rounds only what it displays.
Did you know?
−40 is the one reading where the two everyday scales agree: −40 °C and −40 °F are the same temperature.
Kelvin takes no degree sign. It starts at absolute zero, so 0 K is −273.15 °C, and a change of 1 K is the same size as a change of 1 °C.
Celsius to Fahrenheit
Convert Celsius to Fahrenheit and Fahrenheit to Celsius on one page. Both directions use the same standard relationship, so a forecast, an oven setting, or a body temperature reads correctly whichever scale it started in.
Formula: °F = (°C × 9/5) + 32, and the other way: celsius = (fahrenheit − 32) × 5/9
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| -40 °C | -40 °F |
| -20 °C | -4 °F |
| 0 °C | 32 °F |
| 10 °C | 50 °F |
| 20 °C | 68 °F |
| 21 °C | 69.8 °F |
| 25 °C | 77 °F |
| 30 °C | 86 °F |
| 37 °C | 98.6 °F |
| 38 °C | 100.4 °F |
How to use this converter
- Choose unitsSelect the source and destination units for the measurement.
- Enter a valueThe converted result updates from the maintained unit formula.
- Copy and verifyCopy the result and check the units and rounding required by the destination.
Processing and privacy
Conversion math runs locally in the browser without a calculation API. This category converter can store selected units and values in the page URL so a state can be restored or shared; avoid sharing a URL that contains a value you consider sensitive. Ordinary hosting and analytics are separate from the conversion logic.
Unit guide
Celsius, Fahrenheit, and Kelvin
Temperature scales do not share a common zero point, so most temperature conversions require an offset as well as multiplication. That is why converting °C to °F is not a simple unit factor.
Fahrenheit (°F)
Common for US weather, ovens, and thermostats. Water freezes at 32 °F and boils near 212 °F at sea level.
Kelvin (K)
An absolute scientific scale. A change of 1 K equals a change of 1 °C, and 0 K is absolute zero.
How the math works
Conversion formulas
- Celsius to Fahrenheit°F = (°C × 9/5) + 32Example: (20 × 9/5) + 32 = 36 + 32 = 68 °F
- Fahrenheit to Celsius°C = (°F − 32) × 5/9Example: (98.6 − 32) × 5/9 = 66.6 × 5/9 = 37 °C
- Celsius to KelvinK = °C + 273.15Example: 0 °C + 273.15 = 273.15 K
- Kelvin to Celsius°C = K − 273.15Example: 373.15 K − 273.15 = 100 °C
- Fahrenheit to KelvinK = (°F − 32) × 5/9 + 273.15Example: (32 − 32) × 5/9 + 273.15 = 273.15 K
Quick reference
Temperature conversion chart
Three charts: Celsius to Fahrenheit at the points people actually check, oven settings with their UK gas marks, and Kelvin reference points from absolute zero upward. Formula: °F = (°C × 9/5) + 32.
Celsius to Fahrenheit (weather and body)
| Celsius (°C) | Fahrenheit (°F) | What it means |
|---|---|---|
| −40 °C | −40 °F | Same on both scales |
| 0 °C | 32 °F | Water freezes |
| 10 °C | 50 °F | Cool day |
| 20 °C | 68 °F | Cool room |
| 21 °C | 69.8 °F | Typical indoor target |
| 22 °C | 71.6 °F | Mild room |
| 25 °C | 77 °F | Warm room |
| 30 °C | 86 °F | Hot day |
| 36.5 °C | 97.7 °F | Typical body range start |
| 37 °C | 98.6 °F | Classic average body temp |
| 37.5 °C | 99.5 °F | Low-grade fever zone |
| 38 °C | 100.4 °F | Fever threshold often used |
| 39 °C | 102.2 °F | High fever |
| 40 °C | 104 °F | Dangerously high fever |
| 100 °C | 212 °F | Water boils (sea level) |
Oven temperatures, Celsius, Fahrenheit and gas mark
| Fahrenheit (°F) | Celsius (°C) | Gas mark | Common use |
|---|---|---|---|
| 225 °F | 107.22 °C | 1/4 | Very slow: meringues, drying |
| 250 °F | 121.11 °C | 1/2 | Very slow: slow-cooked stews |
| 275 °F | 135 °C | 1 | Slow: rich fruit cake |
| 300 °F | 148.89 °C | 2 | Slow: casseroles, custard |
| 325 °F | 162.78 °C | 3 | Moderate: simnel cake, milk puddings |
| 350 °F | 176.67 °C | 4 | Moderate: most cakes and biscuits |
| 375 °F | 190.56 °C | 5 | Moderately hot: shortcrust pastry |
| 400 °F | 204.44 °C | 6 | Moderately hot: small cakes, roasting |
| 425 °F | 218.33 °C | 7 | Hot: puff pastry, roast potatoes |
| 450 °F | 232.22 °C | 8 | Hot: bread, pizza |
| 475 °F | 246.11 °C | 9 | Very hot: searing, thin-crust pizza |
Celsius here is the exact conversion, which is why it lands on figures like 176.67 rather than 180. Oven dials are marked in steps of 10, so round to the nearest one: 350 °F is gas mark 4, set 180 °C. Fan or convection ovens run about 20 °C hotter than a conventional oven at the same setting, so drop 20 °C or one gas mark.
Kelvin reference points
| Kelvin (K) | Celsius (°C) | Fahrenheit (°F) | What it means |
|---|---|---|---|
| 0 K | −273.15 °C | −459.67 °F | Absolute zero: no thermal motion |
| 77 K | −196.15 °C | −321.07 °F | Liquid nitrogen boils |
| 255.37 K | −17.78 °C | 0 °F | Zero on the Fahrenheit scale |
| 273.15 K | 0 °C | 32 °F | Water freezes |
| 293.15 K | 20 °C | 68 °F | Comfortable room temperature |
| 310.15 K | 37 °C | 98.6 °F | Human body temperature |
| 373.15 K | 100 °C | 212 °F | Water boils at sea level |
| 5778 K | 5504.85 °C | 9940.73 °F | The Sun's surface |
Kelvin has no degree symbol and no negative values: it starts at absolute zero. A one-kelvin step is the same size as a one-degree-Celsius step, which is why converting between them is addition rather than scaling.
Fahrenheit to Celsius (selected points)
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| 32 °F | 0 °C |
| 68 °F | 20 °C |
| 70 °F | 21.11 °C |
| 72 °F | 22.22 °C |
| 98.6 °F | 37 °C |
| 100 °F | 37.78 °C |
| 212 °F | 100 °C |
Everyday use
Practical temperature conversion examples
Weather and travel
Convert a forecast before traveling between countries that report Celsius and Fahrenheit differently.
Cooking
Translate oven settings from an imported recipe; remember that fan ovens may also require an appliance-specific adjustment.
Science and education
Move between Celsius and Kelvin for laboratory work while respecting the lower limit of 0 K.
Context
Where these units are used
The United States uses Fahrenheit for weather, home thermostats, and most cooking. US news and apps report outdoor highs in °F. Oven knobs and meat thermometers are almost always marked in Fahrenheit.
Celsius is the metric scale used in science and in most other countries for weather. Kelvin is used in science when absolute temperature matters. A US reader often meets Celsius in travel, imported recipes, or lab notes. This temperature converter bridges those scales with the standard formulas.
Frequently asked questions
Is 37 Celsius a fever?
No. 37 °C is 98.6 °F, a classic average body temperature. A fever is often counted from about 38 °C, which is 100.4 °F.
What is 0 Celsius in Fahrenheit?
0 °C is 32 °F. That is the freezing point of water. Use °F = (°C × 9/5) + 32 for any Celsius value.
What is 100 Celsius in Fahrenheit?
100 °C is 212 °F. That is the boiling point of water at sea level. The same formula is °F = (°C × 9/5) + 32.
What is 350 Fahrenheit in Celsius?
350 °F is 176.67 °C. Subtract 32, then multiply by 5/9. Many US recipes list 350 °F as a standard bake.
Is this temperature converter free with no sign-up?
Yes. This converter is free with no sign-up and no account. Use it as often as you need in your browser.
What is 20 C in Fahrenheit?
20 C is 68 F. Multiply by 9/5 and add 32. 25 C is 77 F and 30 C is 86 F.
What is 100 F in Celsius?
100 F is 37.78 C. Subtract 32 first, then multiply by 5/9. 98.6 F is 37 C.
What is the formula for Celsius to Fahrenheit?
Fahrenheit equals Celsius times 9/5, plus 32. Going back, Celsius equals Fahrenheit minus 32, times 5/9.
Does this page convert Fahrenheit to Celsius too?
Yes, both directions run on this page. Enter Celsius to read Fahrenheit, or enter Fahrenheit to read Celsius.