Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin with correct offset and scale handling at extreme values.
Temperature Converter
Enter a temperature in any scale β see the conversion in the others instantly. All calculations run in your browser.
Common Reference Points
How to Convert Between Celsius, Fahrenheit, and Kelvin
The recipe says to preheat the oven to 375Β°F, but your oven only has Celsius markings. Setting it to 375Β°C would incinerate the cake. Enter 375, select Fahrenheit, and the converter instantly shows 190.56Β°C and 463.71 K. The copy button lets you paste the Celsius value straight into your oven timer app. For quick reference, the common temperatures strip at the bottom shows water boiling at 100Β°C / 212Β°F, so you can sanity-check that 190Β°C is in the right ballpark for baking.
The converter handles all six pairwise conversions β Celsius to Fahrenheit, Celsius to Kelvin, Fahrenheit to Celsius, Fahrenheit to Kelvin, Kelvin to Celsius, and Kelvin to Fahrenheit β using the correct linear formula for each. A chemistry student working with the ideal gas law needs temperature in Kelvin. A traveller in Tokyo sees a 35Β°C weather forecast and wants to know if that is "wear shorts" or "stay indoors" in Fahrenheit terms. Each conversion appears instantly, no button press required.
Cooking conversions where the wrong scale ruins the dish
A French pastry recipe calls for baking choux pastry at 200Β°C. If you accidentally set a Fahrenheit oven to 200Β°F, the pastry will not rise at all β choux needs the rapid steam expansion that only happens above 180Β°C (356Β°F). The correct Fahrenheit equivalent is 392Β°F. This tool gives you that conversion instantly, preventing the kind of kitchen disaster that wastes ingredients and time.
A British tourist arriving in New York sees a forecast of 85Β°F and wonders whether to pack a jacket. Converting to Celsius gives 29.4Β°C β warm shorts weather. Conversely, a New Yorker visiting London sees "18Β°C" and needs to know that means 64.4Β°F β a light sweater, not a coat. The converter helps you translate weather intuition across scales without memorising the formula.
A physics experiment measures gas temperature at 22Β°C. For the ideal gas law calculation (PV = nRT), the temperature must be in Kelvin: 22Β°C + 273.15 = 295.15 K. Using 22 instead of 295.15 in the equation would give a pressure reading roughly 13 times too low. The converter shows the Kelvin value alongside Fahrenheit, so students can verify their manual conversion before plugging it into the equation.
How the Temperature Converter Handles Three Different Scales
Unlike length or weight, temperature scales have different zero points and different gap sizes between degrees. The converter handles each of the six possible pairwise conversions with its own formula. Celsius to Fahrenheit multiplies by 1.8 and adds 32. Celsius to Kelvin adds 273.15. Fahrenheit to Celsius subtracts 32 then multiplies by 5/9. The tool applies the correct formula based on which two scales you are converting between, and displays the result to two decimal places.
Why the Celsius-to-Fahrenheit formula is 9/5 plus 32
The 9/5 multiplier (1.8) exists because Fahrenheit and Celsius use different gap sizes. Water freezes at 0Β°C and boils at 100Β°C β a 100-degree span. In Fahrenheit, water freezes at 32Β°F and boils at 212Β°F β a 180-degree span. The ratio of those spans is 180/100 = 9/5. The +32 offset exists because Fahrenheit's zero point is 32 degrees below Celsius's zero point. Combining both corrections gives the formula: Β°F = (Β°C Γ 9/5) + 32. The reverse formula reverses the operations: Β°C = (Β°F β 32) Γ 5/9.
Kelvin is simpler because it shares Celsius's gap size β 1 kelvin equals exactly 1 degree Celsius. The only difference is the zero point: 0 K = β273.15Β°C, so converting between them requires only the 273.15 offset. This makes Kelvin-to-Fahrenheit conversions a two-step process: first convert Kelvin to Celsius (subtract 273.15), then apply the Celsius-to-Fahrenheit formula.
The point where both scales read the same number
Celsius and Fahrenheit intersect at β40 degrees. Setting the two formulas equal and solving: Β°C Γ 9/5 + 32 = Β°C gives Β°C = β40. This means β40Β°C = β40Β°F exactly. It is the only temperature where both scales produce the same number. This is not a useful reference point for everyday life (it is colder than any inhabited place on Earth), but it is a handy verification check: if you convert β40 and get a different number back, your formula is wrong.
The Kelvin scale has no degree symbol because it is an absolute scale defined by fixing the Boltzmann constant at exactly 1.380649 Γ 10β»Β²Β³ J/K. The International Bureau of Weights and Measures (BIPM) dropped the degree symbol in 1967 to distinguish kelvins from degrees Celsius. You write "295.15 K", not "295.15Β°K".
Frequently Asked Questions
How do I convert 200Β°F to Celsius for my oven?
200Β°F equals 93.33Β°C. The formula is (200 β 32) Γ 5/9 = 93.33Β°C. For quick mental estimates, subtract 30 from the Fahrenheit value and divide by 2 β 200 minus 30 is 170, divided by 2 is 85Β°C. That is close but about 8Β°C low, so for baking where precision matters (especially for bread and pastries), use the exact formula or this converter.
What is absolute zero in practical terms?
Absolute zero is 0 K, β273.15Β°C, or β459.67Β°F. At this temperature, all molecular motion theoretically stops. It has never been achieved in practice β the coldest recorded lab temperature is about 0.000000001 K, achieved by cooling rubidium atoms with lasers. For context, outer space is about 2.7 K (β270.45Β°C), which is warmer than absolute zero because of the cosmic microwave background radiation.
Why does my phone weather app show different temperatures than the thermometer?
The difference is usually rounding, not a conversion error. A weather app might display 72Β°F while your thermometer reads 72.2Β°F, because the app rounds to the nearest whole number. The conversion formula itself is exact: 72Β°F = 22.22Β°C. If the discrepancy is larger (more than 2Β°F), check whether one device is measuring Celsius and displaying a converted value β some thermometers display Β°F but measure Β°C internally, introducing a small rounding offset.
Is 37Β°C really normal body temperature?
37Β°C (98.6Β°F) was established as the average normal body temperature by Carl Wunderlich in 1868, based on 25,000 measurements. More recent studies show the average is actually about 36.6Β°C (97.9Β°F), and normal range spans from roughly 36.1Β°C to 37.2Β°C. Body temperature also varies by time of day (lower in the morning, higher in the evening), so 37Β°C is a useful reference point but not a strict threshold for fever.
How do I quickly estimate Celsius to Fahrenheit in my head?
Double the Celsius value and add 30. For example, 20Β°C doubled is 40, plus 30 gives 70Β°F (actual: 68Β°F β close). 30Β°C doubled is 60, plus 30 gives 90Β°F (actual: 86Β°F β a bit off). The estimate works best between 10Β°C and 30Β°C. Outside that range, the error grows because the 9/5 ratio means each Celsius degree is larger than each Fahrenheit degree.