Bok choy is one of the lowest-calorie leafy greens you can add to a meal, and knowing exactly what an ounce supplies makes portion tracking simple. This calculator converts your serving — whether you measure in ounces, grams, cups of chopped leaves, or 100 g servings — into calories and key macros using standard USDA values for raw bok choy.
Because bok choy is roughly 95% water, its energy density is very low: a typical 3 oz handful supplies only about 11 calories. At the same time, it delivers meaningful vitamin K, vitamin C, folate, and calcium. The tool gives you a full macronutrient breakdown plus optional micronutrient estimates, so it works for calorie counting, keto-style net carb tracking, and general healthy eating.
Whether you are meal-prepping stir-fries, adding greens to soups, or building a low-calorie meal plan, this calculator takes the guesswork out of portion sizes.
🥬 Serving Amount
📊 Results
🔬 Micronutrients
🧮 Calculation Breakdown
Step-by-Step Guide
Start by choosing the unit that matches how you measure bok choy: ounces, grams, chopped cups, or 100 g servings. Enter the amount, then click Calculate Calories. The result panel shows calories, carbs, protein, fat, fiber, and net carbs. Checking the micronutrient box adds vitamin K, vitamin C, folate, and calcium estimates.
- Ounces work well with food scales and recipe weights.
- Grams are the most precise option for meal prep.
- A cup of chopped raw bok choy is about 70 g.
- 100 g servings match the standard nutrition reference.
How It Works
The calculator scales USDA raw bok choy values from a 100 g reference portion. The serving multiplier is the serving weight in grams divided by 100.
Calories = 13 × multiplier
Carbs = 2.18 × multiplier
Protein = 1.5 × multiplier
Fiber = 1.0 × multiplier
Net carbs = (2.18 − 1.0) × multiplier
Since 1 oz = 28.35 g, the multiplier for an ounce is 0.2835, giving about 3.7 kcal. A 70 g cup gives about 9.1 kcal.
| Nutrient | Per 100 g | Per 1 oz | Per 1 cup |
|---|---|---|---|
| Calories | 13 kcal | 3.7 kcal | 9.1 kcal |
| Carbs | 2.18 g | 0.62 g | 1.53 g |
| Protein | 1.5 g | 0.43 g | 1.05 g |
| Fat | 0.2 g | 0.06 g | 0.14 g |
| Fiber | 1.0 g | 0.28 g | 0.70 g |
| Net carbs | 1.18 g | 0.33 g | 0.83 g |
Worked Examples
3 oz of raw bok choy: 3 oz = 85.05 g, multiplier 0.8505, calories ≈ 11.1, protein ≈ 1.3 g, net carbs ≈ 1.0 g.
1 cup chopped: 70 g, calories ≈ 9.1, net carbs ≈ 0.8 g — a very low-energy way to add volume to a meal.
250 g salad portion: calories = 13 × 2.5 = 32.5 kcal, with about 5.5 g carbs and 3.8 g protein.
Health and Nutrition Notes
Bok choy is a cruciferous vegetable in the same family as cabbage and broccoli. It is roughly 95% water and delivers useful amounts of vitamin K, vitamin C, folate, and calcium for very few calories. Cooking does not change the energy value, but it drives out water, so cooked bok choy weighs less for the same calories. Adding oil, sauce, or butter will add calories beyond what this calculator reports.
For similar low-calorie leafy green comparisons, try the Brussels sprouts calories per ounce calculator or the Swiss chard calories per gram calculator.
Tips for Accurate Tracking
- Use a digital scale; chopped-cup volumes can vary from 60 to 80 g.
- Measure before cooking. Bok choy can lose over half its weight cooked, which changes how many calories each cooked gram contains.
- Shake off excess water after washing so the weight reflects the vegetable, not rinse water.
- Do not forget oil in stir-fries; this calculator covers only the bok choy itself.
Frequently Asked Questions
How many calories are in one ounce of bok choy? About 3.7 kcal: 13 × (28.35 ÷ 100) = 3.69.
Does cooking change the calorie count? The energy value stays the same, but water loss means cooked bok choy has more calories per gram than raw. Weigh raw whenever possible.
Is bok choy keto-friendly? Yes. Net carbs are about 1.18 g per 100 g raw, so even a large 200 g serving has under 2.5 g net carbs.
Can I use this for baby bok choy? Yes — baby bok choy is similarly moist and nutrient-dense, so calorie totals are effectively the same.