When I’m short on time, one of my favourite techniques is to crank up my oven so everything cooks quicker. Works every time! Here’s how to adjust cooking times for different temperatures.
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 400F (200C) to 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),
60 minutes x 0.89 = 53 minutes.
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, I’d check after 50 minutes.
Common Examples of Different 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
Common Examples of Different 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 Celsius but the results won’t be significantly different.
Other factors to consider when adjusting cooking times for different temperatures.
1. Opening the oven.
Every time you check and open the oven door, the temperature in the oven drops. 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 say veggies for roasting and 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.
3. Shelf Height / Position in the Oven
Even in my fan assisted oven, things cook quicker on the top shelf than they will on the bottom.
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
Have fun in the kitchen!
With love,
Jules x