Food safety guidance is very clear about the destination — 165°F, steaming hot throughout — and almost completely silent about how long that takes. Meanwhile most reheating articles cover exactly one appliance, usually the air fryer, which is only useful if the air fryer happens to be the right tool for what you're holding.
The tables below give times for the same foods across all four methods, so you can pick based on what you have and what you want the food to be like when it's hot.
Crispy Foods
These have a coating or crust that reheating either restores or destroys. The air fryer wins nearly every row here, and the microwave loses nearly every one.
| Food | Air fryer | Oven | Microwave | Stovetop |
|---|---|---|---|---|
| Pizza | 350°F, 3-4 min ✓ | 375°F, 8-10 min | 45-60 sec | Med-low, 4-6 min |
| French fries | 400°F, 3-5 min ✓ | 425°F, 8-10 min | 30-45 sec | Med-high, 4-5 min |
| Fried chicken | 375°F, 5-8 min ✓ | 375°F, 12-15 min | 1-2 min | — |
| Nuggets, spring rolls | 350°F, 3-5 min ✓ | 375°F, 8-12 min | 45-60 sec | Med, 3-4 min |
| Roast potatoes, veg | 350°F, 4-6 min ✓ | 400°F, 10-15 min | 1-2 min | Med-high, 4-6 min |
| Burger patty | 350°F, 3-4 min ✓ | 350°F, 8-10 min | 45-60 sec | Med, 3-4 min |
✓ marks the method that gives the best result, not the fastest. For fries the air fryer runs at 400°F — the highest reheat setting on this page — because a crust is the entire objective and there's nothing delicate inside to overcook.
Moisture-Sensitive Foods
These dry out or toughen when reheated hot and fast. Every row here wants lower heat, added liquid, and usually a cover.
| Food | Air fryer | Oven | Microwave | Stovetop |
|---|---|---|---|---|
| Roast meat slices | 300°F, 3-5 min | 275-300°F, 20-25 min ✓ | 50%, 1-2 min | Low, 3-5 min |
| Steak | 300°F, 3-4 min | 250°F, 15-20 min ✓ | 50%, 30-60 sec | Sear 1-2 min to finish |
| Chicken breast | 325°F, 4-6 min | 325°F, 12-18 min ✓ | 50%, 1-2 min | Low, 4-6 min |
| Fish | 375°F, 4-5 min ✓ | 275-300°F, 10-15 min | 50%, 45-90 sec | Low, 3-4 min |
| Rice | 300°F, 4-5 min | 300°F, 15-20 min | 1-2 min | Low, 4-5 min ✓ |
| Pasta (sauced) | 325°F, 5 min | 300°F, 20 min | 1-2 min | Med-low, 4-6 min ✓ |
Steak is the one row where the best answer is two methods: gentle oven warming to bring the interior up without cooking it further, then a 60-second sear per side if you want the crust back. Reheating steak at high heat simply moves it a doneness level past where you left it.
Bulk and Liquid Dishes
| Food | Air fryer | Oven | Microwave | Stovetop |
|---|---|---|---|---|
| Casserole, baked pasta | 325°F, 8-10 min | 350°F, 20-30 min ✓ | 3-5 min | — |
| Soup, stew, chilli | — unsafe for liquids | 325°F, 20-30 min | 2-4 min | Med, 5-10 min ✓ |
| Bread, garlic bread, pastry | 325°F, 2-3 min | 325-350°F, 5-8 min ✓ | 10-15 sec | Med-low, 2-3 min |
Casseroles are the classic case for covering: foil on for most of the time so the middle heats without the top drying, then off for the last five to ten minutes to brown. Soups and sauces should reach a rolling boil rather than merely being hot.
Adjusting the Times
| Situation | Adjustment |
|---|---|
| Large or family-size portion | Add roughly 40% to the time; don't raise the temperature |
| Straight from the freezer | Add half again or more; lower the oven setting 25°F |
| Dense item (thick slice, deep dish) | Lower the setting and extend, rather than going hotter |
| Fridge-cold and thick | Rest 10-15 min at room temperature first for evenness |
Note the pattern: nearly every adjustment goes toward lower and longer, never hotter. Raising the temperature to speed things up is what produces food that's scorched on the outside and cold in the middle. The reheating calculator applies the portion adjustment for you.
The Rule Behind All of It
Reheat roughly 30-50°F below whatever the food was originally cooked at. Raw food needs high heat to drive surface moisture off and build a crust; a leftover already has that dry exterior, so the same heat overshoots it. Fried chicken cooked at 400°F reheats at 375°F; a casserole baked at 375°F comes back at 350°F.
And keep the two temperatures separate in your head: 165°F is the internal target you verify with a thermometer, while 300-400°F is the setting you choose for texture. Setting an oven to 165°F because that's the number in the safety guidance leaves food sitting for an hour, drying out, never properly hot in the middle.
Frequently Asked Questions
How long does it take to reheat leftovers in the oven?
Most leftovers take 15 to 30 minutes at 325-350°F, with denser dishes like casseroles at the longer end and thin items like pizza at around 8-10 minutes. Meat slices do better lower and slower, around 275-300°F for 20-25 minutes, covered with a splash of liquid.
What is the fastest way to reheat leftovers?
The microwave, by a wide margin — usually one to three minutes. The trade-off is texture: microwaves drive moisture toward the surface rather than away, so anything that was crisp comes out soft. For small portions the air fryer is nearly as fast with far better results, since it needs only two to four minutes of preheat.
Should leftovers be covered when reheating?
Cover anything you want to stay moist — casseroles, rice, pasta, meat slices — and leave uncovered anything you want crisp. A common approach for baked dishes is covered for most of the time, then uncovered for the last five to ten minutes to brown the top.
How long can leftovers be kept before reheating?
USDA guidance is three to four days in the refrigerator. Beyond that, freeze them instead. Reheating does not reset that clock, and it does not make food safe that was left at room temperature for more than two hours.
Can I reheat leftovers straight from frozen?
Yes. USDA guidance allows reheating frozen leftovers without thawing in a saucepan, microwave or oven. Expect it to take considerably longer — roughly half again as much time or more — and use a lower oven setting so the outside doesn't dry out while the centre catches up.