A plain, medium potato (about 150 g, boiled or baked with no extras) has roughly 30–35 grams of carbs.

Quick Scoop

  • Per 100 g of plain potato (no fat or toppings): about 17–21 g of carbs depending on variety and source.
  • A small potato (100 g): around 18–20 g carbs.
  • A typical medium potato (150 g): about 30–35 g carbs.
  • A large restaurant-style potato (250–300 g): about 45–60 g carbs.

Carbs by type and serving

These are approximate totals for plain potatoes (no butter, oil, cheese, etc.):

  • White / yellow / russet potatoes
    • 100 g: ~18–21 g carbs
* 1 medium (150 g): ~30–32 g carbs (simply scaled from 100 g values)
  • Red potatoes
    • 100 g: ~16 g carbs
  • Sweet potatoes
    • 100 g: ~20 g carbs
* 1 medium (130–150 g): ~26–30 g carbs

Most nutrition databases place boiled or baked white potato around 20 g carbs per 100 g and sweet potato just slightly higher.

Does cooking change the carbs?

  • Boiling, baking, or microwaving doesn’t remove carbs in a meaningful way; the total carbs per 100 g of cooked potato stay similar.
  • Frying (fries, wedges, chips) concentrates carbs per 100 g slightly because water is lost and fat is added, increasing calories even if total carb grams in the original potato haven’t changed much.

Net carbs vs total carbs

If you track net carbs (carbs minus fiber):

  • Many potatoes have about 2–3 g of fiber per 100 g , so net carbs will usually be 2–3 g lower than total carbs.
  • Example: a white potato with 21 g carbs and 2 g fiber per 100 g → about 19 g net carbs.

Simple rule of thumb

If you don’t want to weigh:

  • Think “roughly 30 g of carbs per medium potato”.
  • Double the size, and you’re usually close to 60 g of carbs.