A medium baked russet potato contains about 147 calories. That’s for a plain potato with the skin on, weighing roughly 213 grams (about 7.5 ounces), with no butter, sour cream, or other toppings. It’s one of the lowest-calorie ways to eat a filling, satisfying starch.
Calories and Size Breakdown
Potato size varies quite a bit at the grocery store, and calories scale with weight. A medium russet potato (roughly 2.25 to 3.25 inches in diameter) lands at 147 calories. A small russet closer to 5 ounces comes in around 130 calories, while a large one pushing 10 ounces or more can reach 250 to 290 calories. If you’re tracking intake, weighing your potato is more reliable than eyeballing it.
What’s in Those Calories
Nearly all the calories in a baked russet come from carbohydrates. A medium potato has about 36.5 grams of carbs, 3.6 grams of protein, and 3.6 grams of fiber. Fat is negligible, well under a gram. Beyond the macros, a medium russet delivers 620 milligrams of potassium (more than a banana) and 27 milligrams of vitamin C.
Eating the skin matters mostly for fiber. A medium potato with the skin has about 2 grams of fiber; without it, you get roughly 1 gram. Potassium and vitamin C are found predominantly in the flesh, so peeling your potato doesn’t strip away most of the micronutrients.
How Toppings Change the Math
The potato itself is modest in calories. The toppings are where things add up fast.
- Butter: One tablespoon adds about 100 calories. A single pat (the small kind you’d get at a restaurant) adds roughly 35.
- Sour cream: Two tablespoons add about 60 calories.
- Cheddar cheese: A one-ounce serving adds 110 calories. Melted cheese ladled on generously can easily hit 100 calories or more.
- Bacon: Two strips add around 100 calories.
A fully loaded baked potato with butter, sour cream, cheese, and bacon can easily reach 400 to 500 calories. A potato with just a pat of butter and a spoonful of sour cream stays closer to 240 to 250.
Why Potatoes Are More Filling Than You’d Expect
Potatoes score remarkably high on the satiety index, a measure of how full a food keeps you relative to its calorie count. Using white bread as the baseline (100%), boiled or baked potatoes scored 323%, making them the most satiating food tested. For comparison, french fries scored only 116%. The difference comes down to preparation: plain baked or boiled potatoes have high water content, decent fiber, and no added fat, all of which slow digestion and reduce the urge to eat again quickly.
Blood Sugar and the Cooling Trick
Baked russet potatoes have a glycemic index around 69, which puts them in the medium-to-high range. That means they raise blood sugar relatively quickly compared to foods like lentils or sweet potatoes. If blood sugar management matters to you, two things help.
First, eating your potato alongside protein or fat (even a modest amount of sour cream or a chicken breast) slows glucose absorption. Second, cooling changes the starch itself. When a baked russet is cooked and then chilled, its resistant starch content rises from about 3.1 grams per 100 grams of potato to roughly 4.3 grams. Resistant starch passes through your small intestine without being digested, so it doesn’t raise blood sugar the way regular starch does. You can reheat the potato after chilling without losing this benefit. Cooking a batch of potatoes a day ahead and refrigerating them overnight is a simple way to take advantage of this.
The practical effect is modest but real: a cooled or reheated baked potato delivers slightly fewer absorbable calories and produces a gentler blood sugar response than one eaten straight from the oven.