How long it takes for sweet potatoes to get tender depends on their size, whether you’re cooking them whole or cubed, and also the cooking method you’re using. Boiling: Boiled Sweet Potatoes If you're boiling sweet potato cubes, they should be tender in about 20-25 minutes. Air Frying: Roasted Air Fryer Sweet Potato Cubes If you're using an air fryer, cook the sweet potatoes cubes in a preheated air fryer at 380°F for about 15 minutes, depending on the size of sweet potatoes you’re using. Baking: A whole baked sweet potato in a 425°F (220°C) oven will typically take between 45 minutes to an hour to become tender. Microwaving: If you're in a hurry, you can "bake" a sweet potato in the microwave in about 5-8 minutes, depending on the size of the potato and the power of your microwave. Always pierce the sweet potato with a fork a few times before cooking. Slow-Cooking: If you're using a slow cooker, a whole sweet potato can take between 2-4 hours on high or 6-8 hours on low to become tender.