Zucchini is one of the lowest-carb vegetables you can eat. A medium zucchini (about 196 grams) contains roughly 6 grams of total carbohydrates, and a cup of cooked slices has just 3.5 grams. After subtracting fiber, the net carb count drops even lower, making zucchini a go-to vegetable for keto, Atkins, and other low-carb eating styles.
Zucchini’s Carb Count by Serving Size
A half-medium raw zucchini (about 98 grams) has roughly 4 grams of total carbohydrates and 1 gram of fiber, putting net carbs at around 3 grams. Scale that up to a full medium zucchini and you’re looking at about 6 grams of total carbs. One cup of boiled, drained zucchini slices comes in at 3.5 grams of total carbs and 1.3 grams of fiber, so roughly 2.3 grams of net carbs per cup.
These numbers are remarkably low compared to most whole foods. For context, a single medium banana has about 27 grams of carbs, and a medium potato has around 37 grams. Zucchini barely registers.
How Zucchini Fits a Keto Diet
Most keto protocols aim for 20 to 30 grams of net carbs per day. With roughly 2 to 3 net carbs per cup of cooked zucchini, you could eat several generous servings and still have plenty of carb budget left for other foods. Virta Health, a clinic specializing in ketogenic diets, notes that cooked zucchini fits comfortably within a 30-gram daily carb limit.
Zucchini also has a glycemic index of about 15, with a glycemic load near 1 for a typical serving. That’s extremely low on both scales, meaning it causes almost no spike in blood sugar. For comparison, pure glucose scores 100 on the glycemic index. This makes zucchini a safe choice not only for keto dieters but also for anyone managing blood sugar levels.
Zucchini vs. Other Squashes
Not all squash is created equal when it comes to carbs. Zucchini is a summer squash, and summer squashes as a group are light, watery, and low in starch. Winter squashes like butternut, acorn, and spaghetti squash are denser and starchier. A medium winter squash (about 200 grams) contains around 23 grams of carbohydrates, nearly four times what you’d get from the same amount of zucchini.
Yellow summer squash is nutritionally similar to zucchini and can be used interchangeably on a low-carb diet. But if a recipe calls for butternut squash and you’re watching carbs, swapping in zucchini will cut the carb content dramatically.
Zucchini Noodles as a Pasta Swap
One of the most popular low-carb uses for zucchini is spiralizing it into noodles (“zoodles”). The difference is striking: one cup of cooked wheat pasta has about 37 grams of carbohydrates, while one cup of zucchini noodles has just 3.7 grams. That’s a 90% reduction in carbs, along with a drop from roughly 190 calories to about 20.
Zucchini noodles won’t have the same chew as wheat pasta, but they hold sauces well and cook in just a couple of minutes in a hot pan. Overcooking is the most common mistake. Because zucchini is about 95% water, too much heat turns the noodles mushy and releases liquid that waters down your sauce. A quick sauté over high heat, or even eating them raw with a warm sauce spooned on top, gives the best texture.
What Else Zucchini Brings to the Table
Beyond being low in carbs, zucchini is low in calories (about 20 per cup cooked) and contains zero fat. It provides modest amounts of potassium, vitamin C, and B vitamins. The skin holds most of the fiber and micronutrients, so leave it on when you cook. Zucchini won’t replace leafy greens as a nutrient powerhouse, but as a vehicle for sauces, a filler in omelets, or a base for noodle dishes, it adds volume to your plate without adding meaningful carbs or calories.
Grilling, roasting, and sautéing don’t significantly change zucchini’s carb content. Cooking does reduce its volume as water evaporates, so a cup of cooked zucchini started as a larger amount of raw zucchini. But the actual carbohydrate per gram stays essentially the same regardless of cooking method. The only thing that adds carbs is what you pair it with: breading, sugary marinades, or starchy dips.