-to-Fahrenheit-(°F)-Step-6.jpg)
You're standing in the kitchen, flour on your jeans, looking at a recipe from a British blog or an old European cookbook. It says to preheat the oven to 170°C. If you’re in the US, your oven dial or digital display probably only speaks Fahrenheit. You need the answer fast.
The quick math? 170 degrees C to F is exactly 338 degrees Fahrenheit.
Most people just rounded it up to 350°F and call it a day. Honestly, sometimes that works. Other times, it's a recipe for a burnt exterior and a raw middle. There’s a specific science to why 170°C (338°F) exists as a "middle ground" temperature, sitting right between the gentle 160°C and the standard browning temp of 180°C.
The Bare Bones Conversion of 170 Degrees C to F
Let's look at the math for a second. You don't need a PhD, but knowing the formula helps when your phone dies in the middle of a bake. To get from Celsius to Fahrenheit, you multiply the Celsius figure by 1.8 and then add 32.
$$F = (C \times 1.8) + 32$$
So, for 170°C:
- $170 \times 1.8 = 306$
- $306 + 32 = 338$
Exactly 338°F. You won't find a "338" button on a Whirlpool or a Samsung oven. You'll likely have to choose between 335°F or 340°F if you have a digital interface, or just aim the dial slightly below the 350 mark.
Why the "Standard" 350°F Swap Often Fails
In the US, 350°F is the "default" for everything. It’s the vanilla of temperatures. But 350°F is actually closer to 177°C. While a 7-degree difference doesn't sound like a catastrophe, it changes how sugars interact with proteins.
If a recipe specifically calls for 170°C, the author likely wants a slower rise or a more delicate crumb. Using 350°F (177°C) instead might cause the edges of your cake to set before the middle has expanded, leading to that annoying "volcano" crack in the center. It’s also the difference between a chewy cookie and one that’s crunchy all the way through.
The Maillard Reaction: What’s Happening at 170°C?
Cooking isn't just heating stuff up. It’s chemistry you can eat. The Maillard reaction—that magical process where food browns and tastes delicious—really starts kicking into high gear around 140°C to 165°C.
When you set the oven to 170°C (338°F), you are hovering right at the sweet spot where browning happens steadily but not aggressively. At this temperature, the moisture inside the food has time to evaporate at a controlled rate. If you go higher, like 200°C, the surface dries out and burns before the heat can penetrate the center of a thick roast or a dense loaf of bread.
The Role of Fan Ovens (Convection)
Here is where people get tripped up. If you are reading a UK recipe that says 170°C, they often specify "Fan" or "Conventional."
A fan oven (convection) circulates hot air, which makes the cooking more efficient. Usually, you need to drop the temperature by 20 degrees Celsius if you're using a fan. So, if the recipe says 170°C Conventional, and you have a fan oven, you should actually be looking for 150°C—which is about 300°F.
On the flip side, if the recipe says 170°C Fan, and you have a standard American oven without a fan, you might actually need to bump it up to 190°C (375°F) to get the same results in the same amount of time. It’s a bit of a balancing act.
Real-World Applications: When 170°C is Non-Negotiable
Some foods are picky. They don't want to be "roughly" 350 degrees. They want precision.
👉 See also: Why 7th year wedding anniversary gifts are actually the hardest to get right
Macarons and Delicate Meringues
If you're brave enough to tackle French macarons, 170°C is often the upper limit. Many bakers actually prefer 150°C or 160°C, but 170°C is used for "flash browning" certain types of pastry. Go to 180°C and your beautiful pastel cookies turn beige. They crack. They lose their "feet."
Slow-Roasted Meats
While "low and slow" usually implies something down in the 110°C to 130°C range, 170°C is the "fast slow-roast." It’s perfect for a pork shoulder that you want to be able to slice rather than shred. It gives you enough heat to render the fat without turning the muscle fibers into leather.
Dense Fruitcakes and Banana Breads
Heavy batters need time. Because 170°C (338°F) is gentler than the standard 350°F, it allows the heat to reach the center of a thick, wet batter without scorching the top. If your banana bread always ends up raw in the middle but burnt on top, your oven is probably too hot. Try dropping it to the 170°C equivalent.
Troubleshooting Your Oven’s Accuracy
Most home ovens are liars. You set it to 338°F (the 170 degrees C to F conversion), but the internal temperature might be oscillating between 320°F and 360°F.
Ovens work by clicking on and off. They overshoot the target, then cool down, then kick back on. This is why a $10 oven thermometer is the best investment you can make. You might find that to hit a true 170°C, you actually need to set your dial to 350°F because your heating element is weak. Or maybe your oven runs "hot," and you need to set it to 325°F.
The Altitude Factor
If you're baking at high altitudes—say, in Denver or the Swiss Alps—170°C doesn't behave the same way. Air pressure is lower, so moisture evaporates faster. Food can end up dry or "leathery" at standard temperatures. Usually, high-altitude bakers actually increase the temperature slightly and decrease the time. But that’s a rabbit hole for another day. Just know that 170°C at sea level is not 170°C in the mountains.
Practical Steps for Your Next Bake
Don't just wing it. If you're looking at a recipe calling for 170°C, follow these steps to ensure you don't ruin your dinner:
- Check for "Fan" vs "Conventional": If the recipe is from the UK or Australia, this is the most important distinction. Subtract 20°C for fan ovens.
- Aim for 335°F-340°F: If your digital oven moves in 5-degree increments, 340°F is usually the safer bet for meats, while 335°F is better for delicate cakes.
- Use a Middle Rack: 170°C is a moderate temperature, but if your rack is too close to the bottom element, you'll burn the base. Keep it central.
- Trust the Thermometer, Not the Timer: Every oven is different. Use the 170°C/338°F as a guide, but start checking for doneness about 5-10 minutes before the recipe says.
- The "Cold Start" Myth: Some people think you can put food in while it's preheating to 170°C. Don't. The blast of intense heat during the preheat phase can ruin the rise of your dough or sear things unevenly.
Understanding 170 degrees C to F is more than just a math problem; it’s about understanding how heat moves through food. By hitting that 338°F mark, you’re choosing a path of controlled browning and even cooking. Whether it's a sponge cake or a roast chicken, that specific temperature range provides the stability needed for complex flavors to develop without the risk of a scorched finish.
Next time you see 170°C on a screen, don't just default to 350°F. Turn that dial back just a hair. Your taste buds—and your guests—will notice the difference in texture and moisture.