Temperature Converter

How to Use

Using the converter is straightforward. Type any number into the Temperature field at the top of the page, including decimals and negative values. Then open the Scale dropdown and choose the unit your number is currently in: Celsius, Fahrenheit, or Kelvin. As soon as you enter a value, three result cards appear showing the equivalent temperature in all three scales at once, each rounded to two decimal places. There are no buttons to press and nothing to submit; change the value or the scale and the results update immediately. Important: the converter handles only those three scientific scales. For oven dial settings, gas marks, and air fryer values, use the reference charts further down the page, because those are cooking conventions rather than direct math conversions and are not part of the tool.

Why This Tool Is Useful

Temperature conversion shows up constantly in cooking, baking, science homework, travel, and checking the weather abroad, and doing it in your head is error-prone. The converter removes the guesswork by showing Celsius, Fahrenheit, and Kelvin side by side from a single entry, so you never have to remember which formula goes in which direction. For the kitchen specifically, the bundled oven temperature conversion chart bridges the gap between recipes written for different countries and oven types, letting you read across from a gas mark 4 instruction to the right dial setting on a fan oven, or work out an air fryer temperature conversion. Those charts are static reference tables on this page rather than calculator functions, but they sit right beside the tool so everything you need is in one place. It is fast, free, and works on any device without installation.

Oven Temperature Conversion Chart: Celsius, Fan, Fahrenheit and Gas Mark

The most useful thing about temperatures in cooking is being able to read across between systems, which is why this chart leads the page. Recipes from the UK often use gas marks or fan oven settings, American recipes use Fahrenheit, and most modern dials are in Celsius. The oven temperature conversion chart below the article lines all four up so you can convert gas mark to Celsius, find the fan oven equivalent, and read the Fahrenheit value at a glance. It is a printable-style reference table, not a calculator input.

A few landmark values are worth memorising because they appear in so many recipes. A moderate oven of 180 C conventional equals 160 C fan, 350 F, and gas mark 4, the standard setting for cakes, roasts, and most baking. A hot oven of 200 C conventional is 180 C fan, 400 F, and gas mark 6, used for roasting vegetables and crisping. These two settings alone cover a huge share of everyday cooking.

Conventional vs Fan (Convection) Ovens and What Gas Marks Mean

The biggest source of confusion is oven type. A conventional oven heats from elements at the top and bottom, while a fan (also called convection) oven adds a fan that circulates hot air, cooking food faster and more evenly. Because that moving air transfers heat more efficiently, a fan oven runs hotter at the same dial setting, so the standard rule is to reduce the temperature by about 20 C (roughly 25 to 50 F) when a recipe was written for a conventional oven. In practice a recipe calling for 180 C conventional should be set to 160 C on a fan oven.

Gas marks are an older British scale used on gas ovens, numbered roughly from 1/4 up to 9. They are not metric; each whole step adds about 14 C (25 F). Gas mark 1 is a cool 140 C, gas mark 4 is a moderate 180 C, and gas mark 6 is a hot 200 C. Because gas marks are a fixed convention rather than a calculation, you read them from the oven temperature conversion chart rather than from the Celsius-Fahrenheit-Kelvin converter above.

• Conventional oven: heat from top and bottom elements, no fan, the baseline most older recipes assume.
• Fan or convection oven: circulating air, cooks faster, so reduce the stated temperature by about 20 C.
• Gas mark: British gas-oven scale where each whole number is roughly 14 C (25 F) apart.
• Quick anchor: gas mark 4 = 180 C conventional = 160 C fan = 350 F.

Air Fryer Temperature Conversion and Deep-Fry Temperatures

An air fryer is essentially a compact, very efficient convection oven, so an air fryer temperature conversion follows the same logic as a fan oven but a little more aggressively. The general air fryer conversion rule is to reduce the oven temperature by about 20 C (25 F) and cut the cooking time by roughly 20 percent, then check early because small air fryers heat fast and food can brown quickly. For example, a tray of chips written for 200 C in a conventional oven would go into the air fryer at around 180 C for about 20 percent less time.

Deep frying is a different technique with its own target temperatures, measured with a probe or thermometer in the oil rather than read off an oven dial. Getting the oil temperature right keeps food crisp rather than greasy. The bullets below list common deep-fry targets alongside the air fryer rule.

• Air fryer rule: reduce the oven temperature by about 20 C / 25 F and reduce time by about 20 percent.
• Chicken (deep fry): 175 C / 350 F for a juicy interior and crisp coating.
• Chips and fries (deep fry): 190 C / 375 F for golden, crunchy results.
• Fish (deep fry): 185 C / 365 F so the batter sets before the fish overcooks.
• Always check food early in an air fryer; its small chamber heats and browns faster than a full-size oven.

How the Celsius, Fahrenheit, and Kelvin Conversions Work

The converter at the top uses the standard physics formulas, so you can check its work or do a conversion by hand. To go from Celsius to Fahrenheit, multiply by 9/5 and add 32. To go from Fahrenheit to Celsius, subtract 32 and multiply by 5/9. Kelvin shares the same degree size as Celsius but starts at absolute zero, so Kelvin equals Celsius plus 273.15, and Celsius equals Kelvin minus 273.15.

A handy mental check: Celsius and Fahrenheit cross at -40, where both scales read the same number. Water freezes at 0 C / 32 F / 273.15 K and boils at 100 C / 212 F / 373.15 K at sea level. The tool itself only handles these three scientific scales; gas marks and air fryer settings are kitchen conventions, which is why those live in the reference charts rather than in the converter.

• Celsius to Fahrenheit: (C x 9/5) + 32
• Fahrenheit to Celsius: (F - 32) x 5/9
• Celsius to Kelvin: C + 273.15
• Kelvin to Celsius: K - 273.15

Safe Internal Cooking Temperatures for Meat

Oven and air fryer settings control how fast the outside cooks, but food safety and doneness are judged by the internal temperature at the centre of the meat, measured with an instant-read thermometer. These targets are the same regardless of oven type, so they are worth keeping next to the oven chart.

Steak doneness is a matter of preference: medium-rare is around 54 to 57 C (130 to 135 F), while medium is about 60 to 63 C (140 to 145 F). Poultry is a food-safety matter rather than preference and should always reach 74 C (165 F) at the thickest part to be safely cooked. Let larger roasts rest after cooking, as the internal temperature continues to rise a few degrees.

• Medium-rare steak: about 54-57 C (130-135 F).
• Medium steak: about 60-63 C (140-145 F).
• Cooked chicken and other poultry: 74 C (165 F) throughout.
• Use these centre temperatures with the converter above if your thermometer reads in a different scale.

Everyday Reference Points You Can Memorise

Beyond cooking, a few benchmark temperatures make the converter faster to use because you can sanity-check results at a glance. Normal human body temperature is about 37 C (98.6 F). A comfortable room is around 20-22 C (68-72 F). A pleasant warm summer day of 30 C is 86 F, and a hot 40 C day is 104 F, which is useful when reading weather forecasts while travelling.

Knowing the boiling and freezing points also helps verify the tool: if you enter 100 in Celsius you should see 212 F and 373.15 K, and entering 0 in Celsius should return 32 F and 273.15 K. If your figures match those landmarks, the conversion is correct.

Oven Temperature Conversion Chart: Celsius, Fan, Fahrenheit and Gas Mark