Bok choy (pak choi) is one of the lowest-calorie leafy greens you can add to a plate. This calculator converts any portion you actually eat — grams, ounces, chopped cups, leaves, or baby heads — into calories using the standard 100-gram reference values for bok choy.
It also breaks down the same serving into carbohydrates, protein, and fat, and it lets you switch between raw and cooked estimates. A built-in daily calorie target option shows what percentage of a typical 2,000 kcal diet one serving represents.
Whether you are tracking meals in an app, planning a low-energy-density side dish, or simply curious about how far a handful of greens goes, this tool gives a fast, practical estimate — and the step-by-step breakdown shows exactly how the numbers are derived.
🥬 Bok Choy Calories per 100g
Estimate calories, carbs, protein, and fat in any serving of raw or cooked bok choy.
Quick Start
This calculator is designed to be used in under a minute. Pick the unit that matches how you actually measured your portion — a kitchen scale in grams or ounces, a measuring cup of chopped leaves, or a simple count of leaves or baby heads.
- Enter the amount you ate in the serving-amount field and choose the matching unit from the dropdown.
- Select Raw or Cooked to apply the right reference values. Raw bok choy provides about 13 kcal per 100 g; boiled bok choy is about 12 kcal per 100 g.
- Press Calculate Calories to see total kcal, carbohydrate, protein, and fat for your portion, plus what share it represents of a daily target if that option is enabled.
- Use the quick-fill chips (100 g, 1 cup, 1 leaf, 1 baby head) to get instant estimates for common portion sizes without typing.
How the Conversion Works
All portion units are first converted to grams using standard kitchen equivalents: 1 US cup of chopped raw bok choy weighs roughly 70 g, one large leaf weighs about 12 g, and one baby head (including the thick white stems) weighs about 150 g. The calculator then scales the reference nutrient values per 100 g to the actual gram weight:
Calories = weight (g) × kcal per 100 g ÷ 100
The same formula is applied to carbohydrate, protein, and fat. For example, a 70 g portion of raw bok choy gives 70 × 13 ÷ 100 = 9.1 kcal, with 70 × 2.18 ÷ 100 = 1.5 g of carbs and 70 × 1.50 ÷ 100 = 1.1 g of protein. Reference values used by the calculator:
| Nutrient | Raw (per 100 g) | Cooked (per 100 g) |
|---|---|---|
| Energy | 13 kcal | 12 kcal |
| Carbohydrate | 2.18 g | 2.02 g |
| Protein | 1.50 g | 1.12 g |
| Fat | 0.20 g | 0.20 g |
| Fiber | 1.0 g | 1.0 g |
Values are based on USDA FoodData Central entries for pak choi (bok choy); actual figures vary slightly by cultivar, growing conditions, and preparation method.
Worked Examples
Example 1 — One cup of chopped raw bok choy. Assume your cup holds 70 g. Calories: 70 × 13 ÷ 100 = 9.1 kcal. Macros: 1.5 g carbs, 1.1 g protein, 0.1 g fat. That is about 0.5% of a 2,000 kcal daily target — you can eat a very large bowl for minimal calories.
Example 2 — Three boiled baby heads. Three small heads weigh about 450 g total. Using the cooked values: 450 × 12 ÷ 100 = 54 kcal, with 9.1 g carbs and 5.0 g protein. This makes a generous side dish for fewer calories than a single slice of bread.
Example 3 — Six ounces of raw leaves. 6 oz × 28.35 = 170 g. Calories: 170 × 13 ÷ 100 = 22.1 kcal. If you were tracking by volume instead, that is roughly 2.5 cups.
Tips for Accurate Tracking
- Weigh your portion with a kitchen scale when you are logging macros seriously. Cup, leaf, and head estimates vary with plant size, moisture content, and how tightly you pack the cup.
- Raw and cooked weights differ because cooking releases water. If you weigh before cooking, use the raw values; if you weigh after, use the cooked values — do not mix them.
- The white stems contain most of the water weight but almost no extra calories, so a large head is still a low-calorie choice.
- Remember the calculator covers the plain vegetable only. Stir-fry oil, oyster sauce, sesame oil, or butter can add tens to hundreds of calories.
- If you are eating a whole bag or bunch, weigh the entire amount once rather than estimating piece by piece.
Real-World Applications
Bok choy is a staple of volume eating and low-energy-density meal plans because it delivers bulk, water, and micronutrients for very few calories. Nutrition coaches use it in vegetable-heavy stir-fries, soups, and salads; home cooks can use this calculator to portion side dishes consistently; and people tracking calories in apps can check that their logged entries match reality. Because the calorie density is so low, small estimating errors make little practical difference — but the math still helps you understand just how far a pound of greens goes.
Frequently Asked Questions
Is bok choy really only around 13 kcal per 100 g? Yes. It is roughly 95% water, with a little carbohydrate and protein and almost no fat, placing it among the lowest-calorie leafy greens available.
Does cooking change the calorie count? Slightly. Boiling can add water weight and leach a small amount of nutrients, so cooked values per 100 g come out marginally lower. The practical difference is tiny — about 1 kcal per 100 g.
Why does a baby head weigh so much more than a leaf? Baby heads include thick, juicy white stems that hold a lot of water. They add weight and volume but very few calories.
How many calories are in a typical restaurant stir-fry with bok choy? The bok choy itself contributes only 15–30 kcal per serving. The cooking oil, garlic, ginger, and sauces are what push the dish to 150–400 kcal.
Can I use this tool for other leafy greens? Not directly — spinach, kale, and Swiss chard have similar but not identical values. Use the per-100 g figure for the specific green you are logging.
Data sources: USDA FoodData Central · Wikipedia: Bok choy