One cup of shredded iceberg lettuce contains just 10 calories. That makes it one of the lowest-calorie foods you can eat, largely because it’s about 95% water by weight. A medium head of iceberg lettuce (roughly the size of a softball, about 539 grams) comes in at around 75 calories total.
Calories by Serving Size
The calorie count scales predictably with portion size. A single leaf barely registers, while a full head still amounts to less than a snack bar.
- 1 cup shredded (72g): 10 calories
- 1 small head (324g): ~45 calories
- 1 medium head (539g): ~75 calories
- 1 large head (755g): ~105 calories
The glycemic index of iceberg lettuce is 32, which is considered low. In practical terms, eating iceberg lettuce causes almost no change in blood sugar, both because of the low GI and because there are so few carbohydrates per serving to begin with.
What Else Is in Iceberg Lettuce
Iceberg lettuce has a reputation for being nutritionally empty, and while it’s true that darker greens pack more vitamins per bite, iceberg still contributes something. One cup of shredded iceberg provides about 14% of your daily vitamin K (17.4 mcg), a small amount of folate (20.9 mcg, or 5% of the daily value), and 2% of daily vitamin C. Vitamin A is where iceberg falls notably short: just 18 mcg per cup, compared to over 200 mcg in the same serving of romaine.
You also get about 0.86 grams of fiber per cup. That’s modest, but iceberg’s real contribution to your diet is hydration. At 95% water, it’s more hydrating than spinach (91%) or kale (85%), which can matter on hot days or when you’re looking for volume without calories.
How Iceberg Compares to Romaine
The most common comparison people make is iceberg versus romaine, since both end up in salads and sandwiches. Calorie-wise, they’re nearly identical: 10 calories per cup of iceberg versus 8 for romaine. The real gap is in vitamins.
Romaine delivers roughly 11 times more vitamin A (23% of your daily value versus iceberg’s 2%), nearly three times as much vitamin K (40% versus 14%), and triple the folate (16% versus 5%). Fiber is close, with romaine edging ahead at 0.99 grams per cup compared to 0.86 grams. Vitamin C is essentially the same in both.
None of this makes iceberg a bad choice. If you eat a large salad with two or three cups of iceberg, you’re getting meaningful amounts of vitamin K and a solid dose of water and fiber for virtually no calories. Romaine is simply more nutrient-dense per gram.
Getting the Most Out of Your Lettuce
Iceberg lettuce stays fresh longer than most greens when stored properly. At standard refrigerator temperatures (around 41°F or 5°C), you can expect about 14 days of shelf life. At 32°F, the ideal storage temperature used in commercial settings, it lasts 21 to 28 days. Keep it away from fruits like apples and bananas, which release ethylene gas and speed up browning.
For the crispest texture, store a whole head unwashed and uncut, wrapped loosely in a damp paper towel inside a plastic bag. Cut lettuce oxidizes faster, which is why pre-shredded bags tend to brown more quickly than intact heads. Rinse and chop right before you plan to use it.