In this article
- Does spinach have fiber? The numbers for every form
- Is spinach high in fiber, or just low in calories?
- What it takes to get 5 grams of fiber from leafy greens
- Which vegetables have the most fiber compared with spinach?
- The kind of fiber in spinach
- Raw or cooked spinach: a quick decision rule
- What a cup of cooked spinach gives you beyond fiber
- Easy ways to eat more cooked spinach
- The catch: spinach iron is harder to absorb
- Spinach and fiber: what people ask
- Sources
Does spinach have fiber? Yes, and the twist is that it can look like hardly any or quite a lot depending on how you serve it. A cup of raw spinach leaves has only about 0.7 grams, while a cup of cooked frozen spinach has about 7 grams.
Nothing magical happens in the pot. Cooking shrinks the leaves, so far more spinach fits in the same cup.
Below you’ll find the numbers for raw, cooked and frozen spinach, how it ranks among other greens, and the one nutrient catch worth knowing before you count on it for iron.
Does spinach have fiber? The numbers for every form
All of these numbers come from USDA FoodData Central. The Daily Value for fiber is 28 grams, per the FDA.
| Spinach serving | Weight | Fiber | Calories | % Daily Value |
|---|---|---|---|---|
| 1 raw leaf | 10 g | 0.2 g | 2 | 1% |
| 1 cup raw leaves | 30 g | 0.7 g | 7 | 2% |
| 3 cups raw (a big salad base) | 90 g | 2.0 g | 21 | 7% |
| 10 oz bag, raw | 284 g | 6.2 g | 65 | 22% |
| 1/2 cup fresh, boiled and drained | 90 g | 2.2 g | 21 | 8% |
| 1 cup fresh, boiled and drained | 180 g | 4.3 g | 41 | 15% |
| 1/2 cup frozen, boiled and drained | 95 g | 3.5 g | 32 | 13% |
| 10 oz frozen package, cooked | 220 g | 8.1 g | 75 | 29% |
Per 100 grams, raw and boiled fresh spinach are close: 2.2 grams raw and 2.4 grams boiled. The big difference is weight per cup, since a cup of raw leaves weighs 30 grams and a cup of cooked spinach weighs 180.
Frozen spinach comes out ahead even per 100 grams, at 3.7 grams once cooked. USDA’s frozen sample also holds a little less water, 88.9 grams per 100 compared with 91.2 for boiled fresh, so each bite is a bit more concentrated.
Is spinach high in fiber, or just low in calories?
By the cup, raw spinach is not a high fiber food. You’d need nine and a half cups of leaves, a full 10 ounce bag, to reach about 6 grams.
By the calorie, though, spinach is one of the most efficient sources around. A whole bag of raw spinach has just 65 calories, and a cup of cooked spinach has 41.
At 15% of the Daily Value, a cup of cooked spinach makes a real dent in your day. A cup of raw leaves, at 2%, barely registers.
So the honest answer to whether spinach is high in fiber is: cooked, yes; raw, only if you eat a lot of it. Which answer you get comes down to what you do with the leaves before they ever reach your plate.
What it takes to get 5 grams of fiber from leafy greens
This table flips the usual question around. Instead of fiber per cup, it shows how much of each green, and how many calories, you’d need for 5 grams of fiber, using USDA data per 100 grams.
| Green | Amount for 5 g fiber | About how many cups | Calories |
|---|---|---|---|
| Frozen spinach, cooked | 135 g | about 3/4 cup | 46 |
| Fresh spinach, boiled | 208 g | about 1 1/4 cups | 48 |
| Kale, raw | 122 g | about 6 cups | 43 |
| Romaine, raw | 238 g | about 5 cups shredded | 40 |
| Spinach, raw | 227 g | about 7 1/2 cups | 52 |
| Broccoli, raw | 192 g | about 2 cups chopped | 65 |
| Arugula, raw | 313 g | about 15 cups | 78 |
Cooked spinach wins on volume by a wide margin. Three quarters of a cup of cooked frozen spinach does what six cups of raw kale or seven and a half cups of raw spinach would do.
Mixing greens helps a raw salad pull more weight. Two cups of raw spinach give you about 1.3 grams, and adding two cups of raw kale brings the bowl to about 3.0 grams.
Arugula is the outlier. It has the least fiber per 100 grams of these greens, so getting 5 grams from it alone would take a mountain of leaves. Enjoy it for its peppery bite, and let other greens carry the fiber load.
Which vegetables have the most fiber compared with spinach?
Cooked spinach sits in the middle of the cooked vegetable list from the Dietary Guidelines. Here’s how a cup compares:
| Cooked vegetable (1 cup) | Fiber | Calories |
|---|---|---|
| Artichoke | 9.6 g | 89 |
| Green peas | 8.8 g | 134 |
| Brussels sprouts | 6.4 g | 65 |
| Sweet potato | 6.3 g | 190 |
| Broccoli | 5.2 g | 54 |
| Collard greens | 4.8 g | 63 |
| Spinach | 4.3 g | 41 |
| Savoy cabbage | 4.1 g | 35 |
| Corn | 4.0 g | 134 |
Among leafy greens, collards edge out spinach by half a gram. Artichokes and green peas lead the whole list, with more than twice the fiber of spinach per cup.
Spinach’s real edge is calories. Only savoy cabbage on this list comes in lower, and spinach has less than a third of the calories of green peas or corn.
The kind of fiber in spinach
Cleveland Clinic describes the fiber in spinach as mostly insoluble fiber, the type that doesn’t dissolve in water. Registered dietitian Kayla Kopp explains that your body can’t easily break it down, so it adds bulk to stool and helps you feel full longer.
You get that bulk with very little energy attached, since a full cup of cooked spinach has just 41 calories.
Want a gentler way to build more insoluble fiber into your routine? Our gut health guides lay out a simple plan that won’t leave you feeling overstuffed.
Raw or cooked spinach: a quick decision rule
Cleveland Clinic notes that cooked spinach gives you more calcium, iron, fiber, protein and vitamin A per serving, while raw spinach keeps more folate, lutein and vitamin C. USDA data backs that up: raw spinach has 28 milligrams of vitamin C per 100 grams, and boiled has under 10.
Use this rule when you’re deciding how to eat it:
- If fiber is the goal, cook it. Frozen chopped spinach is the easiest win at 3.5 grams per half cup.
- If vitamin C or folate is the goal, eat it raw, in salads or blended into smoothies.
- If you want both, mix it up through the week: a raw salad at lunch, a handful wilted into dinner.
Cleveland Clinic also suggests eating spinach with a healthy fat such as olive oil, avocado, nuts or seeds. Vitamin A is fat soluble, so the fat helps your body use it.
What a cup of cooked spinach gives you beyond fiber
Here’s what one cup of boiled fresh spinach, about 180 grams, provides according to USDA, with % Daily Value from the FDA:
- Vitamin K: about 889 micrograms, more than seven times the Daily Value.
- Vitamin A: about 943 micrograms RAE, just over 100% of the Daily Value.
- Folate: about 263 micrograms, around 66%.
- Magnesium: about 157 milligrams, around 37%.
- Iron: about 6.5 milligrams, around 36%.
- Calcium: about 245 milligrams, around 19%.
- Potassium: about 839 milligrams, around 18%.
Spinach is also packed with lutein and zeaxanthin, yellow pigments that build up in the eye. Cleveland Clinic points to a small study where people who ate half a cup of frozen spinach daily for two months raised their lutein levels and eye pigment.
Easy ways to eat more cooked spinach
Since cooking is what turns spinach into a real fiber source, these ideas lean that way:
- Stir half a cup of thawed frozen spinach into pasta sauce, soup or chili.
- Fold a big handful of fresh leaves into scrambled eggs until they wilt.
- Mix cooked chopped spinach into rice, lentils or mashed potatoes.
- Layer it into lasagna or stuffed shells in place of some of the cheese.
- Blend raw leaves into a berry smoothie for a vitamin C boost.
A whole 10 ounce package of frozen spinach stirred into a pot of soup that serves four adds about 2 grams of fiber to every bowl. Nobody at the table has to eat a salad to get it.
Looking for more spinach dishes that do the fiber math for you? Our recipe eBooks are full of simple, high-fiber meals built around greens.
Curious how all these grams fit your own day? Our fiber calculator shows you a personal daily target in a few seconds.
The catch: spinach iron is harder to absorb
Myth vs fact: spinach is a top iron source
Myth: Spinach is one of the best ways to get iron.
Fact: Spinach has a respectable amount of iron on paper, but it’s non-heme iron, the plant form your body absorbs less well than the heme iron in meat. Cleveland Clinic notes that spinach also contains oxalates and polyphenols, compounds that can bind to iron and hold it back.
Cooking helps a little on paper. USDA lists 3.6 milligrams of iron per 100 grams of boiled spinach versus 2.7 milligrams raw.
The fix is simple. Cleveland Clinic suggests pairing spinach with vitamin C, for example cooking it with potatoes or blending it with berries and citrus, and saving the glass of milk for another meal, since calcium may also reduce iron absorption.
Spinach and fiber: what people ask
Is spinach high in fiber?
Cooked spinach is a good source, with about 4.3 grams per cup, or 15% of the Daily Value. Raw spinach is low per cup at about 0.7 grams, because a cup of leaves weighs only 30 grams.
Does cooking spinach destroy the fiber?
No. Boiled spinach has about 2.4 grams of fiber per 100 grams, compared with 2.2 grams raw. Cooking shrinks the leaves, so you eat much more spinach per cup.
Is frozen spinach as good as fresh?
For fiber, frozen is better per cup. Half a cup of cooked frozen spinach has about 3.5 grams, while half a cup of boiled fresh spinach has about 2.2 grams.
How much fiber is in a bag of spinach?
A 10 ounce bag of raw spinach has about 6.2 grams of fiber and only 65 calories. That’s about 22% of the Daily Value.
Is spinach or kale higher in fiber?
Raw kale has more fiber per 100 grams, at 4.1 grams versus 2.2 for raw spinach. But a cup of cooked spinach gives you 4.3 grams, about what 5 cups of raw kale would.
Which leafy greens have the most fiber?
Among cooked greens, collards have about 4.8 grams per cup and spinach about 4.3. Raw kale leads the raw greens at 4.1 grams per 100 grams.
Does spinach help with constipation?
It can. Its fiber is mostly insoluble, which adds bulk to stool, according to Cleveland Clinic. A cup of cooked spinach gives you about 4.3 grams toward that.
Sources
- U.S. Department of Agriculture, Agricultural Research Service. “Spinach, raw (168462); Spinach, cooked, boiled, drained (168463); Spinach, frozen, cooked, boiled, drained (169288); Kale, raw (168421); Lettuce, cos or romaine, raw (169247); Arugula, raw (169387); Broccoli, raw (170379).” FoodData Central, SR Legacy. 2019. fdc.nal.usda.gov
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. “Food Sources of Dietary Fiber.” Dietary Guidelines for Americans, 2020 to 2025. dietaryguidelines.gov
- U.S. Food and Drug Administration. “Daily Value on the Nutrition and Supplement Facts Labels.” 2026. www.fda.gov
- Cleveland Clinic. “7 Reasons You Should Eat More Spinach.” 2024. health.clevelandclinic.org
