Broccoli Calories & Nutrition Calculator

At just 35 calories per 100 grams, cooked broccoli delivers a concentration of vitamins and minerals that few other foods can match calorie-for-calorie ^[1]. A single cup of boiled broccoli (about 156 g) provides over 100% of the Daily Value for vitamin C (101 mg, 112% DV) and roughly 183% of the Adequate Intake for vitamin K (220 mcg) — two nutrients with well-documented roles in immune function and bone metabolism respectively.

This exceptional calorie-to-nutrient ratio is what nutritionists call high nutrient density. For context, you would need to eat nearly 300 calories of cooked white rice to match the vitamin C in 35 calories of steamed broccoli. Broccoli also stands out among vegetables for its folate content (108 mcg/100 g) — higher per serving than green beans (33 mcg), cauliflower (44 mcg), or kale (13 mcg). While spinach delivers more folate per calorie, broccoli's folate is accompanied by its exceptional vitamin C and K profile, making it one of the most well-rounded vegetable sources of this B-vitamin ^[1].

A 2024 comparative study by Hwang and Lee analyzed broccoli prepared by different cooking methods and confirmed that both boiled and steamed broccoli retain substantial polyphenol and flavonoid content, though the magnitude of retention depends heavily on the method used ^[11]. This makes method selection — not just portion size — a meaningful lever for maximizing the nutritional return from every serving.

The way you cook broccoli matters more than most people realize. A landmark study by Bongoni et al. (2014) in *Plant Foods for Human Nutrition* measured glucosinolate retention across three cooking methods and found that steaming retained 42% more total glucosinolates than boiling with a cold-water start at medium firmness ^[2]. Boiling with a hot-water start performed slightly better than cold-start boiling (41% loss vs. 50% loss), but neither method approached steaming, which showed only a 17% decrease even after 22 minutes ^[8].

These findings were reinforced by Hwang and Lee (2024), who reported that boiling decreased broccoli's total glucosinolate content by 5.74–18.64% across nine identified compounds, while steaming actually increased glucosinolate content compared to raw broccoli — likely because heat loosens the plant cell matrix and improves extractability without the leaching effect of immersion water ^[11].

Vitamin C follows a similar pattern. Raw broccoli contains approximately 89.2 mg per 100 g, steaming preserves about 65 mg, and boiling retains around 64.9 mg ^[1]. The difference between steaming and boiling is modest for vitamin C, but the glucosinolate gap is substantial. Antioxidant activity, measured by DPPH and ABTS assays, also decreases more with boiling than with steaming ^[11].

The practical takeaway: steam broccoli for 4–5 minutes to medium firmness to optimize both nutritional retention and sensory acceptance. Bongoni et al. found that medium-firm broccoli scored highest for overall consumer liking regardless of cooking method ^[2], making this the sweet spot where nutrition and palatability converge.

Broccoli belongs to the Brassicaceae family and contains glucosinolates — sulfur-containing phytochemicals that are largely unique to cruciferous vegetables. The most abundant glucosinolate in broccoli is glucoraphanin, which is converted to the bioactive compound sulforaphane through the action of an enzyme called myrosinase ^[5]. Sulforaphane has attracted significant research interest for its antioxidant and anti-inflammatory properties in laboratory studies ^[3].

Here is the problem: cooking denatures myrosinase. When broccoli is boiled or steamed, the enzyme that converts glucoraphanin to sulforaphane is largely inactivated. However, research by Zhao et al. (2025) in *Molecular Nutrition & Food Research* demonstrated that the gut microbiota can compensate. Their study showed that 7 days of cooked broccoli consumption significantly increased the ability of cecal microbiota to hydrolyze glucoraphanin into sulforaphane and other bioactive isothiocyanates, in both lean and obese mice ^[5].

This finding has a practical implication: regular broccoli consumption trains your gut bacteria to extract more sulforaphane from cooked broccoli over time, even though the plant's own myrosinase is heat-inactivated. The study also found increased colonic NQO1 activity — a detoxification enzyme associated with cellular protection against oxidative stress — in both lean and obese subjects after broccoli feeding ^[5].

To maximize sulforaphane when eating cooked broccoli, consider the mustard seed trick: adding a small amount of raw mustard seed powder (which contains active myrosinase) to cooked broccoli can restore the enzymatic conversion. Alternatively, chopping raw broccoli and letting it sit for 40 minutes before cooking allows myrosinase to act on glucoraphanin before the enzyme is denatured by heat ^[4].

While vitamin C gets most of the attention, broccoli's micronutrient profile extends far deeper. Cooked broccoli provides 141 mcg of vitamin K per 100 g — exceeding the entire adult Adequate Intake in a single serving. Vitamin K₁ (phylloquinone), the dominant form in broccoli, is essential for blood coagulation and plays a key role in bone mineralization through the carboxylation of osteocalcin ^[1].

Folate is another standout: at 108 mcg per 100 g cooked (about 27% of the adult DV), broccoli is one of the richest vegetable sources of this B-vitamin critical for DNA synthesis and neural tube development during pregnancy ^[1]. Unlike folic acid supplements, the natural folate in broccoli (5-methyltetrahydrofolate) does not mask vitamin B12 deficiency — a safety advantage noted in clinical nutrition literature.

The mineral profile, while less concentrated than in legumes, is well-balanced: potassium (293 mg/100 g) is an essential electrolyte, calcium (40 mg) contributes to the daily requirement from plant sources, and iron (0.67 mg), though modest, is accompanied by broccoli's high vitamin C content — which enhances non-heme iron absorption by up to 3-fold when consumed together ^[6].

The base calorie count of broccoli is low — but the method you use to prepare it can shift the final number considerably. Plain boiled or steamed broccoli sits at 35 kcal/100 g. The moment you add fat through roasting, stir-frying, or sautéing, the calorie density increases because water evaporates while oil is absorbed into the florets.

Roasted broccoli without added oil reaches approximately 55 kcal/100 g due to water evaporation concentrating the nutrients; toss in a teaspoon of olive oil and the figure climbs to 65–75 kcal/100 g depending on the amount used. Stir-fried broccoli with minimal oil lands around 52 kcal/100 g. A single teaspoon of olive oil adds 40 calories, butter adds 36, and a tablespoon of Parmesan adds 21 — seemingly small amounts, but they can double the calories of a side dish when combined ^[7].

Classic broccoli pairings carry their own caloric weight. Hollandaise sauce (2 tbsp) adds 87 calories and 9.1 g fat. Cheddar cheese (1 oz) adds 113 calories. Broccoli soup made with cream can reach 120–180 kcal per cup depending on the recipe. The calculator above lets you layer these additions precisely so the total reflects your actual plate, not a generic USDA entry.

For those tracking macros, the cleanest high-volume approach is steamed broccoli with lemon juice and garlic — roughly 37 kcal per 100 g with practically no added fat, while gaining extra vitamin C from the lemon and a trace of manganese from the garlic. It is the kind of preparation that lets you fill a plate for under 100 calories while still hitting meaningful vitamin K and folate targets.