A cup of raw spinach contains just 7 calories. That makes it one of the lowest-calorie foods you can eat, and you’d need to consume an almost absurd amount before it made a meaningful dent in your daily intake. Here’s what the numbers look like across different serving sizes and preparations.
Calories in Raw Spinach
One cup of raw spinach (about 30 grams) has 7 calories, 1 gram of protein, and 1 gram of fiber. Because raw spinach leaves are so light and airy, a cup barely weighs anything. Even a large salad bowl packed with 3 or 4 cups of raw spinach comes in under 30 calories.
By weight, raw spinach has roughly 23 calories per 100 grams. For context, that’s less than half the calories in an equal weight of carrots and about a tenth of what you’d get from the same weight of rice.
Calories in Cooked Spinach
One cup of boiled spinach has about 41 calories. That sounds like a big jump from 7 calories per cup raw, but the spinach itself hasn’t changed. Cooking just shrinks the volume dramatically. About 10 to 12 cups of raw spinach leaves cook down into a single cup. So that cup of cooked spinach represents a much larger quantity of the same plant.
Whether you steam, sauté, or boil spinach, the calorie content per gram stays essentially the same. The only thing that changes your calorie count is what you cook it in. A tablespoon of olive oil or butter added to the pan contributes far more calories than the spinach itself.
How Spinach Compares to Other Greens
Calorie-wise, spinach and kale are nearly identical. A cup of raw kale also has 7 calories. The differences between these greens show up in their vitamin profiles, not their energy content. Spinach delivers significantly more vitamin K (121% of the daily value per cup versus 68% for kale), more vitamin A (16% versus 6%), and five times as much folate (15% versus 3%). Kale, on the other hand, provides more than double the vitamin C.
Spinach also edges out kale in iron, magnesium, and potassium per cup, though by smaller margins. Both greens are essentially interchangeable from a calorie standpoint, so choosing between them is more about flavor preference and which nutrients you’re trying to get.
Why Spinach Feels Filling for So Few Calories
Spinach has a surprisingly high fiber content relative to its calories. Per 100 grams, it contains about 3.2 grams of total fiber, roughly three-quarters of which is insoluble fiber (the kind that adds bulk and helps move food through your digestive system). That fiber-to-calorie ratio is part of why a big spinach salad can feel satisfying despite being so low in energy.
There’s another factor at play too. Spinach contains compounds called thylakoids, which are membranes found in the plant’s cells. Research on overweight women found that consuming a thylakoid-rich spinach extract reduced hunger, increased feelings of fullness, and curbed cravings for highly palatable foods. The mechanism involves boosting a satiety hormone called GLP-1, which plays a role in appetite and reward signaling in the brain.
One Thing to Know About Spinach Nutrients
Spinach looks impressive on paper for minerals like calcium and iron, but your body doesn’t absorb all of what’s listed on a nutrition label. Spinach is high in oxalates, naturally occurring compounds that bind to calcium and reduce how much you actually take in. This doesn’t make spinach less nutritious overall. It still delivers meaningful amounts of folate, vitamin K, vitamin A, magnesium, and potassium. But if you’re counting on spinach as a primary calcium source, you’ll absorb less than you would from lower-oxalate foods like kale or broccoli.
Cooking spinach can reduce oxalate levels somewhat, particularly boiling (since some oxalates leach into the water). This is one case where cooked spinach may give you a slight nutritional edge over raw, beyond just the convenience of fitting more into a single serving.