Russet potatoes, sweet potatoes, and red potatoes each have different baking times, and their size plays just as big a role as the variety. So how long do you cook a potato in the oven? Most medium russet potatoes need about 60 minutes at 400°F, but the real answer depends on a few things.
This guide breaks it all down by type and size. You will get exact times, temps, and simple steps that work every time.
How Long Do You Cook A Potato In The Oven
The short answer: a medium potato takes 45 to 60 minutes at 400°F. Small ones can be done in 30 to 40 minutes. Large ones may need 70 to 90 minutes.
Oven temperature and potato size matter more then most people think. A big potato at 350°F can take well over an hour. The same potato at 425°F might finish in 50 minutes.
Quick Time Chart By Potato Type
- Russet potato, medium: 60 minutes at 400°F
- Russet potato, large: 75 to 90 minutes at 400°F
- Sweet potato, medium: 45 to 55 minutes at 400°F
- Red potato, medium: 35 to 45 minutes at 400°F
- Baby potatoes: 25 to 30 minutes at 400°F
These times assume you prick the skin and bake on a rack or sheet pan. Foil-wrapped potatoes cook a bit faster but the skin turns soft instead of crisp.
Why Size Beats Variety
A potato is mostly water and starch. Heat has to travel from the skin to the center. The bigger the distance, the longer it takes.
A small red potato and a small russet can finish within a few minutes of each other. But a large russet can take twice as long as a small sweet potato.
So when you plan dinner, check the size first. Then adjust the time based on the type.
Baking Times For Each Potato Variety
Russet Potatoes
Russets are the classic baking potato. They have thick skin and a dry, fluffy inside. They also take the longest to cook.
- Small (under 6 oz): 40 to 45 minutes
- Medium (6 to 10 oz): 55 to 65 minutes
- Large (over 10 oz): 75 to 90 minutes
Russets are done when a fork slides in with no resistance. If the center feels firm, give it 10 more minutes.
Sweet Potatoes
Sweet potatoes cook a little faster then russets. Their flesh is softer and holds more moisture.
- Small: 35 to 40 minutes
- Medium: 45 to 55 minutes
- Large: 60 to 75 minutes
You will know a sweet potato is ready when it starts to leak sticky syrup from the ends. That is a good sign, not a bad one.
Red Potatoes
Red potatoes have thin skin and waxy flesh. They bake faster than russets and hold their shape well.
- Small: 30 to 35 minutes
- Medium: 35 to 45 minutes
- Large: 50 to 60 minutes
They are great for a quick side dish. Just don’t overbake them or the skin gets tough.
Other Common Potatoes
Yukon golds sit between russets and reds. A medium one takes about 45 to 55 minutes. Fingerlings are small and thin, so 25 to 30 minutes is usually enough.
Temperature And Time Combinations That Work
Most recipes call for 400°F. But you can bake at other temps if you adjust the time.
- 350°F: add 15 to 20 minutes to standard times
- 375°F: add 5 to 10 minutes
- 400°F: standard times above
- 425°F: subtract 5 to 10 minutes
- 450°F: subtract 10 to 15 minutes, watch closely
Higher heat gives you a crispier skin and a faster bake. Lower heat is more forgiving if you need to keep the oven free for other dishes.
One tip: put a sheet pan under the potatoes. They sometimes drip, and you dont want a messy oven.
Step By Step: How To Bake A Potato
- Heat the oven to 400°F.
- Wash and scrub each potato under cold water.
- Dry them well with a towel.
- Prick the skin 6 to 8 times with a fork.
- Rub a little oil and salt on the skin. This helps it crisp.
- Place potatoes directly on the oven rack or a sheet pan.
- Bake for the time listed for its size and type.
- Check doneness by squeezing gently with a towel. It should give easily.
- Let them rest 5 minutes before cutting open.
Skip the foil if you want crispy skin. Foil steams the potato and makes the skin soft. Some people prefer that, so it is your call.
How To Tell When A Potato Is Done
Use a fork or a thin knife. Stick it into the center. If it goes in with no pushback, the potato is done.
You can also use a instant-read thermometer. A fully baked potato reads about 210°F inside.
If the center is still firm, put it back in for 10 minutes and check again.
Common Mistakes To Avoid
- Not pricking the skin. Steam builds up and the potato can burst.
- Baking cold potatoes straight from the fridge. Let them sit out 20 minutes first.
- Using the wrong size estimate. Weigh or measure before you set the timer.
- Checking too early and letting heat escape. Wait at least 30 minutes.
- Wrapping in foil when you want crisp skin.
Another common slip is baking at 450°F and walking away. High heat works, but the window between done and burnt gets small.
Making It Faster
Short on time? There are a few tricks that cut the bake time without ruining the texture.
- Cut large potatoes in half lengthwise. They bake in about 30 to 35 minutes.
- Par-cook in the microwave for 5 minutes, then finish in the oven for 20 minutes.
- Use smaller potatoes. Baby potatoes are ready in under 30 minutes.
- Raise the heat to 425°F and check at the 40 minute mark.
The microwave trick works well. You still get some crisp skin from the oven finish, and dinner lands on the table much sooner.
Storing And Reheating
Baked potatoes keep in the fridge for 3 to 4 days. Wrap them tight or put them in a sealed container.
To reheat, put them in a 350°F oven for 15 minutes. The microwave works too, but the skin will soften. A skillet with a little oil can bring back some crisp.
So the next time you wonder how long to cook a potato in the oven, start with the chart above. Match the time to the type and size, check with a fork, and you will get a perfect potato every time.