Convert °F to °C degrees Fahrenheit ↔ degrees Celsius Free Online Secure
Type a temperature in degrees Fahrenheit and read it in degrees Celsius at once. The relation is exact by definition, the arithmetic happens in your browser, and nothing is sent anywhere.
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Common values — Convert °F to °C (degrees Fahrenheit ↔ degrees Celsius)
| °F | °C |
|---|---|
| -40 | -40 |
| 0 | -17.7777777778 |
| 32 | 0 |
| 50 | 10 |
| 68 | 20 |
| 77 | 25 |
| 98.6 | 37 |
| 212 | 100 |
Where these units come from
Fahrenheit set his zero in 1724 at the coldest thing he could make reliably — a brine of ice, water and salt — and put body heat near 96, so that his scale could be divided and divided again. Celsius published his in 1742 the other way up, with 0 for boiling and 100 for freezing; it was turned around after his death, which is why he is remembered for a scale he never used. Kelvin is the only one of the four that begins where there is nothing left to take away: absolute zero. Since 2019 it is defined by fixing the Boltzmann constant rather than by the triple point of water, so the kelvin no longer depends on a particular substance. Rankine is Fahrenheit's degree counted from absolute zero, and Réaumur, with 80 degrees between freezing and boiling, survives mostly in old recipes and in a few cheese dairies.
Where you meet them
Celsius runs weather, cooking and medicine almost everywhere; Fahrenheit does the same work in the United States and keeps a foothold in oven settings and in American recipes. Kelvin belongs to physics, to the colour temperature of lamps and screens, and to anything cold enough that negative numbers would be a nuisance. Rankine appears in American thermodynamics, and Réaumur mainly in historical texts — which is exactly why an old recipe can mislead someone reading it as Celsius.
Questions people ask
Is it true that −40 °C and −40 °F are the same?
Yes, and it is the only place the two scales meet. Fahrenheit degrees are smaller than Celsius ones — nine of them to every five — and the two scales start from different zeros; the one temperature where the difference in size and the difference in starting point cancel out exactly is minus forty. Below that, the Fahrenheit number is the lower of the two.
Why can't I just double the number to double the temperature?
Because three of these scales have arbitrary zeros. Twenty degrees Celsius is not twice as hot as ten; it is ten degrees further along a scale whose zero was chosen for the convenience of water. Only kelvin and Rankine begin at absolute zero, where there is genuinely nothing left, so only on those two does doubling the figure mean doubling the thermal energy. That is also why every conversion here adds or subtracts as well as multiplying.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
American recipes in a metric kitchen: Fahrenheit into Celsius
Open an American cookbook and the oven is at 350, the candy thermometer reads 240, the roast is done at 165 and the dough proofs at 80. Every number is in degrees Fahrenheit, while the dial on a kitchen abroad shows Celsius. To convert °F to °C, subtract 32 and divide by 1.8: 350 °F is 176.7 °C, 240 °F is 115.6 °C and 165 °F is 73.9 °C. The calculator above does the arithmetic as you type, and the sections below show what the figures mean for baking, roasting, sugar work, preserving and drinks.
You will find the formula with worked examples, a short profile of each scale, a comparison, a long set of practical cases from the kitchen and the slips to avoid. The arithmetic runs in your browser, and what you type is not sent anywhere. For food safety, always follow the guidance of your local authority.
How to convert °F to °C: subtract 32, then divide by 1.8
The formula
The formula is °C = (°F − 32) × 5/9, or (°F − 32) ÷ 1.8. So 212 °F is (212 − 32) ÷ 1.8 = 100 °C, 32 °F is 0 °C and 68 °F is 20 °C. To go the other way, multiply by 1.8 and add 32.
Worked examples
A moderate oven at 350 °F is 176.7 °C, usually set at 180. A hot oven at 450 °F is 232.2 °C. A slow oven at 300 °F is 148.9 °C. A freezer at 0 °F is −17.8 °C, and a refrigerator at 40 °F is 4.4 °C.
Why you subtract first
Fahrenheit puts 32 at the freezing point of water, so the offset has to come off before the size of the degree changes. If you divide first and subtract afterwards, the answer is wrong by 17.8 degrees.
A quick sanity test
Above −40 the Celsius figure is always the smaller one. If a “convert °F to °C” calculation returns a bigger number, the formula has been turned around.
The Fahrenheit scale
The scale of American recipes
On the Fahrenheit scale water freezes at 32 and boils at 212. American cookbooks, ovens, candy thermometers and meat probes use it throughout, so any recipe that comes from the United States speaks in these degrees.
Where it appears
Cookbooks, oven dials, food-safety charts and kitchen thermometers.
The Celsius scale
The scale of most of the world
On the Celsius scale water freezes at 0 and boils at 100. It is the scale of European and most other recipes, oven dials and food-safety rules, and the one your local regulator uses.
Where it appears
Oven dials, food-safety rules, laboratory thermometers and weather reports.
Fahrenheit against Celsius
One Celsius degree is 1.8 Fahrenheit degrees. A recipe step that raises the temperature by 18 °F therefore raises it by 10 °C. American oven dials move in steps of 25 °F, or about 14 °C, while European ones move in steps of 10 °C, or 18 °F, which explains why a conversion rarely matches a dial exactly.
The formula is exact, with rounding only on display. The traps are the order of operations and mixing a temperature with a temperature difference.
Where the conversion shows up
Oven settings
250 °F is 121 °C, 275 °F is 135 °C, 300 °F is 149 °C, 325 °F is 163 °C, 350 °F is 177 °C, 375 °F is 191 °C, 400 °F is 204 °C, 425 °F is 218 °C, 450 °F is 232 °C, 475 °F is 246 °C and 500 °F is 260 °C. Round to the nearest 10 °C on a European dial, so 350 °F becomes 180 °C and 425 °F becomes 220 °C. A “convert °F to °C” calculation for each step of a recipe keeps the baking on track.
Meat and food safety
Poultry is safe at an internal temperature of 165 °F, which is 73.9 °C. Ground beef needs 160 °F, which is 71.1 °C. Pork and fish are cooked to 145 °F, or 62.8 °C. A steak is medium-rare at 130 to 135 °F, which is 54.4 to 57.2 °C. Check the thickest part with a probe.
Candy and sugar
Soft-ball stage is 235 to 240 °F, which is 112.8 to 115.6 °C. Firm ball is 245 °F, or 118.3 °C, hard ball 250 to 265 °F, or 121 to 129 °C, and hard crack 300 to 310 °F, or 149 to 154 °C. Sugar work needs precise readings, so a thermometer with the right scale and a careful conversion save a batch.
Bread and dough
Lean bread bakes at 450 °F, which is 232 °C, at the start and is done when the inside reaches 205 to 210 °F, or 96 to 99 °C. Enriched bread such as brioche is done at 190 °F, or 88 °C. Active dry yeast is proofed in water of 105 to 115 °F, which is 40.6 to 46.1 °C, and dough rises best at 75 to 80 °F, or 24 to 27 °C.
Sous-vide cooking
Sous-vide recipes quote exact water temperatures: 130 °F, or 54.4 °C, for medium-rare steak, 145 °F, or 62.8 °C, for soft eggs and fish, and 150 °F, or 65.6 °C, for chicken breast. Many circulators accept both scales, but older ones show Fahrenheit only. A one-degree error in Celsius is 1.8 degrees Fahrenheit, which is visible in texture.
Reheating and holding food
Leftovers are reheated to 165 °F, which is 73.9 °C. A buffet keeps hot food above 140 °F, which is 60 °C, and cold food below 40 °F, which is 4.4 °C. Between those two limits lies the danger zone. Catering staff trained in the US use the Fahrenheit numbers, and a “convert °F to °C” calculation gives their European colleagues the same limits.
Freezers and refrigerators
A freezer should hold 0 °F, or −17.8 °C, and a refrigerator 40 °F or below, or 4.4 °C. A cooler with ice stays near 32 °F, or 0 °C. Food kept in a warm car at 90 °F, or 32 °C, enters the danger zone fast, so the American two-hour rule becomes one hour above 90 °F.
Roasting vegetables
Most vegetables roast well at 400 to 425 °F, which is 204 to 218 °C. Potatoes brown at 425 °F, or 218 °C, and delicate fish at 375 °F, or 191 °C. Pizza at home goes in at 475 to 500 °F, or 246 to 260 °C, on a preheated stone, and few European ovens reach it, so a “convert °F to °C” calculation tells you to use the maximum setting.
Fan ovens
Fan ovens run hotter in effect, and recipes often advise lowering the set temperature by 25 °F, or about 14 °C. Some European guidance says 20 °C, which is 36 °F. A cook who follows an American recipe on a fan oven should lower the converted value by 15 to 20 °C, then check progress earlier than the recipe says.
Oven thermometers
Home ovens can be 25 to 50 °F off, or 14 to 28 °C, which a “convert °F to °C” calculation on the thermometer reading will reveal. A cheap oven thermometer hung on the rack shows the real temperature. If it reads 325 °F, which is 163 °C, when the dial says 350 °F, which is 177 °C, you have found a 14 °C error that will change the baking time and colour.
Baby bottles and bath water
Milk for babies is warmed to about 98.6 °F, which is 37 °C, and the bath water to 98 to 100 °F, or 36.7 to 37.8 °C. American baby products print these numbers in Fahrenheit. Test a few drops on the inside of the wrist and use a thermometer if you can.
Spreadsheet formulas
Put Fahrenheit values in column A and use =(A2-32)*5/9 in column B. For the reverse, use =B2*9/5+32. For differences, use =A2*5/9 with no 32. Add a column that rounds to the nearest 10 for oven dials with =MROUND(B2,10). Label the unit in each header.
Rounding and precision
The formula is exact, but a kitchen thermometer reads to within a degree or two. Rounding 176.7 °C to 177 °C is fine for a thermometer, and to 180 °C for a dial. Keep one decimal for sugar work and body temperature, and whole degrees for the oven.
A mental shortcut
Subtract 32, halve the result, then add a tenth of that half. For 350 °F: 318 halved is 159, plus 15.9 gives 174.9, close to the exact 176.7. The usual trick of subtracting 30 and halving gives 160, which is too low for oven work, but it does well for room temperatures.
Chocolate tempering
Dark chocolate is melted to 115 to 120 °F, or 46 to 49 °C, cooled to 80 to 82 °F, or 27 to 28 °C, and rewarmed to 88 to 90 °F, or 31 to 32 °C. Each step matters, because a two-degree error on the Celsius dial is almost four Fahrenheit degrees. Chocolatiers working from American texts keep a conversion chart beside the thermometer and run a “convert °F to °C” calculation at each stage.
Landmarks to memorise
32 °F is 0 °C, 50 °F is 10 °C, 68 °F is 20 °C, 86 °F is 30 °C and 104 °F is 40 °C. At a baking temperature each 50 °F step is about 28 °C. With a few landmarks you can place any recipe figure between two known values without a calculator.
Reference ladder
0 °F is −17.8 °C. 40 °F is 4.4 °C. 100 °F is 37.8 °C. 165 °F is 73.9 °C. 212 °F is 100 °C. 300 °F is 148.9 °C. 350 °F is 176.7 °C. 400 °F is 204.4 °C. 450 °F is 232.2 °C. A ladder like this helps when a recipe jumps from one stage to the next.
Checking by reversing
To check any convert °F to °C result, multiply it by 1.8 and add 32 to see whether you return to the start. If 350 °F became 176.7 °C, then 176.7 times 1.8 is 318, and adding 32 gives 350. A second test is the direction: above −40 the Celsius value is smaller.
Temperature differences in recipes
When a recipe says to cool the syrup by 30 degrees, the size depends on the scale: 30 °F is 16.7 °C. When it says to reduce the oven by 25 °F, that is 14 °C. For differences, divide by 1.8 and do not subtract 32.
Digital probes and scale buttons
Most digital probes have a button that switches between °F and °C. Check the display before trusting a reading: a probe that shows 74 is done if it is in Celsius, but dangerously raw if it is in Fahrenheit. Make the check part of every cook, and when in doubt run a “convert °F to °C” calculation yourself.
Altitude cooking
At 3,000 metres water boils near 194 °F, which is 90 °C. Eggs, rice and beans cook more slowly, and candy stages move lower: the soft-ball stage that is 235 °F at sea level shifts down by about 1 °F for every 500 feet. American high-altitude baking charts give corrections in Fahrenheit, which need converting for a metric oven.
Jam and the gel point
Jam sets at about 220 °F, which is 104.4 °C, roughly 8 °F above the boiling point of water on the day. At high altitude, where water boils below 212 °F, the setting point drops by the same amount. A cook at 1,500 metres, where water boils at about 95 °C, aims for around 99 °C, or 211 °F, and a “convert °F to °C” calculation on the recipe figure shows how far below the usual 104 °C that is.
Canning and preserving
Water-bath canning keeps the jars in water at 212 °F, or 100 °C, which suits acidic foods such as fruit and pickles. Low-acid foods need a pressure canner: 240 °F, or 116 °C, at 10 psi, and 250 °F, or 121 °C, at 15 psi. American canning guides are written in Fahrenheit and psi, and each figure needs converting for a metric canner.
Deep frying
Deep frying is done at 350 to 375 °F, which is 177 to 191 °C. Doughnuts prefer 360 to 375 °F, or 182 to 191 °C, and fish and chips 350 °F, or 177 °C. Oil above 400 °F, or 204 °C, may smoke and break down. A clip-on thermometer in Fahrenheit is common in American kitchens, and a “convert °F to °C” calculation puts it beside your electric fryer dial.
Barbecue and the smoker
Low and slow barbecue runs at 225 to 250 °F, which is 107 to 121 °C. Brisket and pulled pork are tender at an internal 195 to 205 °F, or 91 to 96 °C. A turkey breast is done at 165 °F, or 74 °C, and the thigh at 175 °F, or 79 °C. Grilling steaks over high heat means 450 to 550 °F, or 232 to 288 °C.
Custards and sauces
Egg custards thicken at 170 to 175 °F, which is 77 to 79 °C, and curdle past about 185 °F, or 85 °C. Hollandaise stays smooth below 160 °F, or 71 °C. A thermometer in the sauce helps more than guesswork, and a quick convert °F to °C on each target keeps both recipe and thermometer scales aligned.
Coffee and tea
Brewing coffee is best with water at 195 to 205 °F, or 90.6 to 96 °C. Black tea wants 212 °F, or 100 °C, and green tea only 175 °F, or 79.4 °C. Steamed milk for a latte is heated to 140 to 155 °F, which is 60 to 68 °C. Above 160 °F, or 71 °C, the milk tastes scorched.
Yogurt, kombucha and fermentation
Yogurt cultures grow at 110 °F, or 43 °C. Kombucha ferments at 75 to 85 °F, or 24 to 29 °C, and a sourdough starter at 78 °F, or 25.6 °C. A cool kitchen slows each of these, and a warm one speeds them up, so a few Fahrenheit degrees make a visible difference over a day.
More values for convert °F to °C
A longer list of conversions
If the value you need is not in the first list, these further conversions may be close enough to read off directly:
- -273.15 °F = -169.528 °C
- -100 °F = -73.3333 °C
- -20 °F = -28.8889 °C
- 10 °F = -12.2222 °C
- 15 °F = -9.44444 °C
- 25 °F = -3.88889 °C
- 30 °F = -1.11111 °C
- 50 °F = 10 °C
Common slips when you convert °F to °C
Dividing before subtracting
Subtract 32 first. Dividing 350 by 1.8 gives 194, far from the correct 176.7.
Converting a difference as a temperature
A drop of 18 °F is a drop of 10 °C, with no 32 subtracted.
Ignoring the dial steps
An exact conversion may not exist on your dial. Pick the nearest setting and watch the food.
Short answers
How do I convert °F to °C?
Subtract 32 and divide by 1.8.
What is 350 °F in Celsius?
176.7 °C.
What is 212 °F in Celsius?
100 °C.
When do the scales agree?
At −40.
Does my number leave my device?
No, the calculation runs in your browser.
More pages and a wrap-up
For other temperature conversions see Convert °F to °R, Convert °F to °Ré, Convert °R to °C, Convert °Ré to °C, Convert °C to K, Convert km to mi, Convert mi to km, Convert L to gal, Convert gal to L. The reverse direction is Convert °C to °F.
In short, a “convert °F to °C” calculation means subtracting 32 and dividing by 1.8, then writing the unit beside the answer. Your number is computed locally, with no account and no upload.