When I’m short on time, one of my favorite techniques is to increase the temperature of my oven so everything cooks quicker. Here’s how to adjust cooking times for different temperatures with my simple cooking time calculator.
This works both when you just have one thing to cook in the oven and want it to happen faster OR when you have multiple things to cook at different temperatures and need them to be in the oven at the same time.
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How to adjust cooking times for different temperatures.
STEP 1. Work out the percentage difference in temperature.
Start Temperature / End Temp = % Difference.
For example going from start temp of 400F (200C) to end temp of 450F (230C)
= 400 / 450 = 0.89 or 89%
STEP 2. Adjust Expected Time
Multiply initial time by the % Difference
Back to our example, if something takes 60 minutes at 400F (200C), it will take 60 minutes x 0.89 = 53 minutes at 450F (230C).
STEP 3. Add a safety margin
This isn’t an exact science, and you don’t want to burn dinner, so I check earlier just to be sure.
For our example if the new calculated time is 53 minutes at the higher temperature, I would set a timer to check after 50 minutes.
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Video Tutorial Instructions
Convert Cooking Times for Different Temperatures.
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RESOURCES: Common Examples of Different Oven Temperatures – Fahrenheit
If starting time = 30 minutes
250F instead of 350F = 1.40 = 42 minutes
350F instead of 400F = 1.14 = 34 minutes
300F instead of 350F = 1.16 = 35 minutes
400F instead of 450F = 1.12 = 33 minutes
350F instead of 250F = 0.71 = 21 minutes
400F instead of 350F = 0.88 = 26 minutes
350F instead of 300F = 0.86 = 25 minutes
450F instead of 400F = 0.89 = 27 minutes
NOTE: These calculations work the same for a conventional oven, a convection oven and a traditional oven. Unless the recipe specifies otherwise assume the temperatures are written for a convection (fan assisted) oven. There are very few conventional-oven recipes written these days.
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RESOURCES: Common Examples of Different Oven Temperatures – Celsius
If starting time = 30 minutes
120C instead of 180C = 1.40 = 42 minutes
180C instead of 200C = 1.14 = 34 minutes
150C instead of 180C = 1.16 = 35 minutes
200C instead of 230C = 1.12 = 33 minutes
180C instead of 120C = 0.71 = 21 minutes
200C instead of 180C = 0.88 = 26 minutes
180C instead of 150C = 0.86 = 25 minutes
230C instead of 200C = 0.89 = 27 minutes
NOTE: There will be slight differences in your calculations for Celcius but the results won’t be significantly different.
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Other factors to consider when adjusting baking time for different temperatures.
1. Opening the oven.
Every time you check and open the oven door, the temperature in the oven drops because you are losing hot air. Which will increase the cooking time.
This can result in you checking, opening, checking, opening and things ending up taking significantly longer than planned.
2. Space around the food
If you have equal amounts of for example, veggies for roasting and you cram one sample into a small roasting dish but spread the other sample out on your largest rimmed baking sheet, there will be a significant difference in the time each takes to cook.
The more space, the easier it is for the heat to penetrate and the quicker the cooking time. So the second example where the food is more spread out will cook significantly quicker then when the food is packed tightly.
3. Shelf Height / Position in the Oven
Even in my fan assisted oven, things cook quicker on the top shelf than they do on the bottom shelf.
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Oven Temperature Conversion Guide
(Oven Temperature Conversion Chart)
NOTE:
F = degrees Fahrenheit (degrees f)
C = degrees Celsius (degrees c)
GM = gas mark
200F = 100C – super slow cooking for meats etc. similar to a slow cooker.
300F = 150C = GM2 – regular slow roasting.
350F = 180C = GM4 – for most sweet baking, cookies, cakes etc. Roasting nuts.
400F = 200C = GM6 – Perfect roasting temperature for roasting veggies, roasting chicken, roast beef, roast lamb, cooking baked dishes, reheating food. Basically good for cooking everything else.
480F = 250C = GM9 – aka ‘cranking it’. For pizza, fast roast fish and times when I’m short on time.
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Can I cook something at a higher temperature for a shorter time?
Absolutely! I do this all the time. The thing to watch out for is that you’re going to get quicker browning at a higher temperature. For small individual pieces of food like chicken thigh fillets, chicken wings, chops, steaks, fish fillets, diced vegetables or meatballs this isn’t a problem because the food will cook through.
BUT for a whole chicken, whole fish, pork roast, ham on the bone or other large cut of meat you will need to be careful that you don’t get burnt on the outside and have the internal temperature still raw in the middle. Generally for these larger cuts it’s better to stick to the lower temperature for the longer time and check the temperature with a meat thermometer to be certain you avoid foodborne illness.
Sometimes I do start these large cuts at a higher temperature for 10 or 15 minutes to speed up the cooking then reduce the temperature back down.
For sweet treats and baked goods I generally stick to the recipe cooking temperature and time because it can be easy to burn the edges before the middle is cooked. But if I’m really rushed I will tweak the temperature slightly higher by no more than 50F / 20C / 1 Gas Mark above the recommended temperature.
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Can I bake something at a lower temperature for longer?
ABSOLUTELY! If you have more time cooking at lower temperatures can be great because you will get more even cooking.
Avoiding the burnt edges on your cake and the under baked middle (which sinks as it cools) is an excellent idea.
Lower temperatures are great because they give you a larger window of time between when your dish is cooked perfectly and when it gets over cooked.
For meat cooking lower slower cooking usually results in more tender succulent meat or poultry.
There is a time when lower temperatures do NOT help. For bread baking, pizza or anything where you’re looking to get significant rise in the oven (like a souffle) it’s better to stick to the recipe temperature because you need the heat to cause the air to expand or the steam to be created which gives a light springy texture.
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What happens if you bake at 350 instead of 400?
Thhe baking time is going to be a little longer. From our conversion chart above, 350F instead of 400F will take 1.14 more time. So something that takes 30 minutes at 400F will take 34 minutes at 350F.
Or for my fellow metric system users. Cooking at 180C instead of 200C will take 34 minutes instead of 30 minutes.
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How to cook 2 things in the oven at the same time at different temperatures
It’s simple. Use the oven set point for the most delicate item or for the one with the lowest temperature. Then expect the other item to take longer than normal.
Also put the more delicate / lower temp dish on the lower shelf as well.
For example. If I wanted to cook a cheesecake at 350F (180C) and a lasagna at 400F (200C). The cheesecake would be the more ‘delicate’ dish because it will curdle if over baked. So I would set the oven to 350F (180C) put the cheesecake on the lower shelf and the lasagna on the top. Then when the cheesecake was cooked. If the lasagna needed longer (which it probably will) I’d increase the temperature to finish it more quickly.
For more on this see my Ultimate Oven Temperature Guide.
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How to cook things that need different temperatures?
The safest way is to set the oven for the lowest temperature item, knowing that the recipes with a higher temperature will end up taking longer. If you want an esimate of how much longer use the baking time conversion calculator above.
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4 Common MISTAKES when adjusting cooking times for different temperatures.
Mistake 1. Forgetting to check.
Whenever I over cook something, the majority of the time it’s because I’ve been distracted and either not noticed the timer or forgotten to set the timer to begin with.
The solution: Always set a timer every time you put something in the oven. I use my phone timer instead of one in the kitchen so that if I leave the kitchen and get distracted in the garden or else where I will hear the timer and not burn my dinner.
Mistake 2. Opening the oven too frequently.
Every time you check and open the oven door, the temperature in the oven decreases which increases the cooking time. This can have a significant impact of the meal taking significantly longer too cook. For cakes it is especially problematic because the lower temperature results in the cake not rising enough and the final texture being denser than desired.
The solution: Resist the urge to repeatedly open the oven. Once you have checked and decided the food needs longer. Be generous in your estimation of how much longer it will take and then set a timer and do not open the oven until the timer has gone.
Mistake 3: Too many oven dishes.
When you are cooking for more people than usual and you have a lot of favorite oven recipes, it’s easy to forget that oven space can be a big bottle neck in the kitchen.
The solution: When planning your meal think through exactly how many dishes are going to require the oven and plan your menu so you can either cook some things in the oven in advance or choose some dishes which use a different cooking process and don’t need the oven at all.
Mistake 4: Crowding the oven.
It can be tempting to squeeze lots of food onto each tray and fill up the oven so there is food on every shelf. The less space there is between the shelves and around each piece of food (ie the more crowded), the longer everything will take to cook.
The solution: Again in the planning phase, be realistic about what you will be able to fit in the oven. But if it’s already too late to change plans – do your best to spread the food out as much as possible and be mindful that things will take longer to cook in a crowded oven.
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Why is 350 F (180C) the magic number for baking?
Great question! It’s because this moderate temperature allows sufficient heat to cook the cake or pie though to the middle without over browning or burning around the edges.
That being said, I often bake at a slightly higher temperature of 400F (200C) if I’m in a hurry which generally doesn’t cause any problems.
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How does using a fan assisted oven change baking times?
Most modern recipes are written for fan assisted ovens because the more even heat distribution helps bake more evenly. I always use the fan setting and just keep in mind if it’s an old recipe which was writem for conventional ovens I will check at the earlier range of time.
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More Cooking Skills
- The Ultimate Oven Temperature Guide
- Is High Temperature Roasting Safe?
- 3 Unusual Ideas for Your Slow Cooker
- Are You Using Enough Salt?
- How to Open Any Jar
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Have fun in the kitchen!
With love,
Jules from Stonesoup
(your favourite Australian Food Scientist)