Calibrate your oven's temperature
Ovens may gradually become out of calibration when they're older, and oftentimes you can allow for this by adjusting your recipes. But when you get a new oven, you should return to cooking your recipes as they were originally intended. When it's time to make an adjustment, you can calibrate your oven's temperature (up to 35°F higher or lower) instead of altering your recipes every time you cook.
Note: This adjustment does not affect the broiling or self-cleaning temperature and is retained in the oven's memory after a power failure.
Note: Due to the way your oven operates, oven thermometers are not an accurate way to measure your oven's temperature and should not be referred to when calibrating your oven. The proper measurement tool (if you do not want to use the recipe trial method described here) is a thermocouple.
First, pick a test recipe you're very familiar with. You may need to cook this recipe several times before settling on the exact desired amount of calibration you want. You can use any recipe you like, but a suggestion is to use a cookie recipe and make small batches of 3-6 cookies, or any other recipe you can make small batches of.
Now that you've selected a recipe, cook it exactly as written, especially when it comes to the temperature and time in the oven.
Note: If your oven has previously been calibrated, set the calibration amount back to 0 before you begin your testing (see step 5). This will save you from having to do extra math later.
If the food comes out perfect, you're done! Otherwise, if the food is undercooked, try the recipe again with a temperature setting higher than the recipe indicated. Or if the food is burnt, try the recipe again with a temperature setting lower than the recipe indicated. Remember to keep the length of time the exact same in every test.
Repeat the previous step until you get the food just right, and make a note of what the temperature you set it to was when you get the results you want. With a little math, compare that to the original temperature specified by the recipe. You now know how much you need to calibrate by.
To actually calibrate the oven by the amount you decided on, set the Temperature Adjustment in your oven's settings. For ovens with a Settings or Options menu, Thermostat Adjustment can be found in the menu. For other models, press and hold two buttons (for example Broil and 1) until the display shows ADJ 0. For the exact steps specific to your model see your user manual.
Now this is important: Make sure the adjustment is in the correct direction! If your food was coming out undercooked and you adjusted the temperature higher than the original recipe, your adjustment should be positive (+). If your food was coming out burnt and you adjusted the temperature lower than the original recipe, your adjustment should be negative (-). You can toggle between positive/negative adjustment before entering the amount. See your user manual for steps specific to your model.
After confirming you have the right direction set, enter the adjustment amount (up to 35°F) and confirm or save the setting.
If you want to confirm the adjustment is in place, try your test recipe one more time but return to using the original temperature in the recipe. It should come out just how you want!
Note: If your cooking results are not consistent (you cook things the exact same way but the results come out different each time), or if a 35°F adjustment isn't enough to get the results you want, see our guide for Oven does not cook well.