How to Test Your Oven Temperature Without a Thermometer

Step 1: To test if your oven is running cold: Preheat oven to 375° Fahrenheit. (186° Celsius)

Step 2: Place granulated sugar in a small oven-proof dish or on a cookie sheet lined with aluminum foil, and place in oven for 15 minutes.

Step 3: If your oven is properly calibrated, the sugar will melt. If it is too cold, the sugar will not melt.

Step 4: To test if your oven is running hot: Preheat oven to 350° Fahrenheit (177° Celsius).

Step 5: Place granulated sugar in a small oven-proof dish or on a cookie sheet lined with aluminum foil, and place in oven for 15 minutes.

Step 6: If your oven is properly calibrated, the sugar will not melt (but may brown somewhat). If your oven is running hot, the sugar will melt.

Step 7: Note: ovens do not maintain a constant temperature, but cycle above and below it, so it is possible that the sugar may melt at 350° if your oven is correctly calibrated but has an extreme cycle (15° Fahrenheit, 8° Celsius). It's a good idea to follow up this test with a real thermometer.