The Baked Potato Calculator determines optimal oven baking time from potato weight and oven temperature, accounting for the nonlinear (radius-squared) relationship between potato size and heat penetration time. Prevents the common failure of a browned exterior with a dense, undercooked interior.
60
minutes
1,000
g
98
°C
250
g
60
minutes
1,000
g
98
°C
250
g
A baked potato seems simple — but the most common failure mode is a potato that is beautifully browned outside and still dense, starchy, and undercooked inside. The disconnect occurs because oven heat penetrates to the center by conduction through the potato's tissue, and that process scales with the square of the radius rather than linearly with mass. The calculator for baked potato cooking time accounts for this physics to give accurate time estimates across the full range of potato sizes and oven temperatures.
A potato in an oven absorbs heat primarily through convection from the oven air and radiation from the oven walls. The heat then conducts inward through the potato tissue toward the center. The time for the center to reach target temperature scales as:
t ∝ R² / (α × ΔT)
where R is the potato radius, α is the thermal diffusivity of potato tissue (approximately 1.4 × 10⁻⁷ m²/s — similar to most dense vegetables), and ΔT is the temperature difference between oven and target center temperature. Key implications: doubling the potato radius increases baking time approximately fourfold (not doubled); a 300 g Russet needs roughly 50% more time than a 200 g potato, not 50% more. The target internal temperature for fully cooked potato is 93–96°C (200–205°F) — at this point, starch granules have fully gelatinized and the texture transforms from waxy-starchy to light and fluffy. Use this online calculator for any potato weight and oven temperature. The mashed potato calculator handles potato quantities for large-batch preparation.
Not all potatoes bake equally. Variety selection significantly affects texture outcome:
For an authentic restaurant-quality baked potato, choose a large Russet (350–400 g), pierce with a fork 8–10 times, coat with a thin layer of oil and salt for a properly seasoned and crispy skin, and bake at 200°C (400°F) for 60–75 minutes directly on the oven rack — never wrapped in foil, which traps steam and produces a steamed rather than baked potato.
Wrapping baked potatoes in foil is common in steakhouse settings where potatoes are held warm for extended periods — but it fundamentally changes the cooking mechanism from baking to steaming. Foil-wrapped potatoes retain all moisture released from the tissue, producing a steam environment that softens the skin and creates a slightly waxy interior texture. The skin remains soft rather than developing the leathery crispiness characteristic of a properly baked jacket potato. If you are baking for immediate service, foil wrapping is unequivocally inferior for texture. If holding baked potatoes for 30+ minutes in a warming oven, foil prevents drying out — a valid operational compromise in food service contexts. The vegetable roasting calculator and vegetable cooking calculators cover related vegetable preparation timings.
At high altitude (above 3,000 feet / 900 m), water boils at lower temperatures (94°C at 3,000 ft, 89°C at 6,000 ft) and ovens may behave slightly differently due to reduced air density. For baked potatoes, the primary effect is that the steam within potato tissue exits at slightly lower pressure, marginally affecting heat transfer. In practice, altitude adds approximately 5–10% to baking times at elevations above 5,000 feet. The more significant effect of altitude on baking manifests in raised doughs and cakes where CO₂ expansion rates change — for dense starchy vegetables like potatoes, the correction is modest.
Cooking time is estimated using a size-based baseline adjusted by a temperature factor:
Base time (at 200°C): Small = 45 min, Medium = 60 min, Large = 75 min, XL = 90 min
Temperature factor: 180°C × 1.15 (15% longer), 200°C × 1.0, 220°C × 0.88 (12% shorter)
Cook time = Base time × Temperature factor
Target internal temperature: 98°C regardless of potato size or oven setting.
The calculated time is an estimate based on an average potato of the selected size class. Actual potatoes vary in shape and density, so begin checking 5–10 minutes before the suggested time with a fork or thermometer. The potato is done when a skewer slides in with no resistance and the internal temperature reads approximately 98°C.
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Results
Four medium potatoes baked at standard 200°C take about 60 minutes. Start checking at 55 minutes.
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Results
At a higher temperature the large potatoes take about 66 minutes — faster than at 200°C but watch for skin darkening after 55 minutes.
The most reliable method is an instant-read thermometer: the center should reach 98°C (208°F). Alternatively, pierce the potato with a sharp knife or skewer — if it slides in with virtually no resistance, the potato is done. The skin should also feel slightly crispy and the potato should yield slightly when squeezed with an oven mitt.
Foil traps steam and produces a soft skin — more like a steamed potato than a baked one. For crispy skin, bake unwrapped directly on the oven rack. Foil can be useful for keeping baked potatoes warm after cooking without drying them out.
Yes, in about 5–8 minutes per medium potato, but the texture differs significantly. Microwaved potatoes lack the crispy skin and have a somewhat denser interior. For speed, microwave 80% of the way through, then finish in a hot oven for 10–15 minutes to crisp the skin.
Russet (Idaho) potatoes are the gold standard for baking due to their high starch content, which produces the characteristic light, fluffy interior. Avoid waxy varieties like red or new potatoes — they are better suited to boiling and roasting.
Steam builds up inside the potato as moisture evaporates during cooking. Piercing the skin allows this steam to escape. Without piercing, pressure can build and — in rare cases — the potato can burst in the oven or when cut open.
400°F is approximately 204°C, which is essentially the same as the 200°C setting in this calculator. It is the most commonly recommended temperature for baked potatoes.
Yes. Some recipes call for 160–170°C for 90–120 minutes. The result is a very even interior but the skin will be less crispy. This works well if you are cooking potatoes alongside a slow-roasting cut of meat.
Allow to cool completely, then refrigerate in an airtight container for up to 3 days. Reheat in an oven at 200°C for 15–20 minutes to restore crispiness, or slice open and microwave on high for 2–3 minutes for a quicker option.
Yes, with a small adjustment. Sweet potatoes have a similar density to Russet potatoes, so the timing is approximately the same. However, sweet potatoes contain more sugar and will caramelize and darken faster, so keep the oven at 200°C or below and check them 10 minutes earlier.
Oven calibration, altitude, potato shape (longer/flatter potatoes cook faster than spherical ones of the same weight), and refrigerator-cold potatoes all affect cooking time. Always treat calculated times as starting points and verify doneness physically.
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