How to Cook Old Fashioned Oats in the Microwave

by Susan Lundman ; Updated November 15, 2017

Oatmeal That's Cooked Just Right

If instant oatmeal seems too gooey for your taste, and if you don't have 15 to 20 minutes in the morning to wait for steel oats to cook, old-fashioned oats cooked in the microwave give you the best of both worlds. You can also customize your cereal, cooking it just the way you like. Add a few seconds to the basic time for a dense chewiness, or subtract a few seconds for a looser texture.


  • In a microwave set on high power, old-fashioned rolled oats take 2 to 3 minutes to cook, depending on the consistency you like in your oatmeal.

How to Microwave

Set on high, microwaving old fashioned oats takes just a few minutes for a single serving. Most directions call for 1/2 cup oatmeal and 1 cup water, but you may prefer 1/3 cup oats and 2/3 cups water or 3/4 cup oats and 1 1/2 cups water. You can also substitute milk for the water in the recipe for a more creamy oatmeal with more protein than in oatmeal made with water.

Measure the oats and tap water into a large cereal bowl using a ratio of 1 part oats to 2 parts water. Add a pinch of salt if you want, but it's not necessary, especially if you add flavorful additional ingredients before or after the oatmeal cooks.

Microwave the cereal on high for 2 to 3 minutes. Begin with a 2 1/2 minute time period if you've used 1/2 cup of oats, increasing the time if you've used more oats and water and decreasing it if you've used fewer oats or like a more dense result.

Better Tasting Oatmeal

When you microwave your oatmeal with additional ingredients, you add both flavor and nutrition. Add dried cranberries or raisins before cooking, and add spices such as cinnamon, allspice or a tablespoon of cocoa mix after cooking. Keep other ingredients on hand in your cupboard for ready mixing into the cereal, such as toasted chopped walnuts, slivered almonds or shredded sweetened coconut.


  • Stovetop cooking for one serving of oatmeal takes a bit longer than microwaving and requires stirring, but it also produces good results. To cook on the stovetop, boil 1 cup of milk or water for each 1/2 cup of oats. Then stir in the oats, and cook for 4 to 6 minutes, depending on whether you want a dense or loose texture, stirring occasionally so the oats don't stick to the sides or bottom of the pan.

About the Author

Susan Lundman began writing about her passions of cooking, gardening, entertaining and recreation after working for a nonprofit agency, writing grants and researching child development issues. She has written professionally for six years since then. Lundman received her M.A. from Stanford University.