Choy — also known as bok choy, pak choi, or Chinese cabbage — is a leafy green vegetable prized for its mild flavor and impressive nutritional profile. This calculator helps you quickly determine the dietary fiber content in various types of choy based on the amount you plan to eat, whether raw or cooked.
Whether you're tracking your daily fiber intake for digestive health, managing a low-fiber diet, or simply curious about the nutritional value of your stir-fry ingredients, this tool provides accurate estimates using standard USDA nutrition data. Simply select the choy variety, enter the weight or serving size, and choose your preparation method to get an instant fiber count.
🥬 Choy Fiber Calculator
How to Use This Tool
Using the Choy Fiber Calculator is straightforward. Start by selecting the type of choy you have — options include bok choy, baby bok choy, choy sum, and napa cabbage. Next, enter the amount you plan to eat. You can specify the quantity in grams, ounces, or cups (chopped). The calculator also lets you choose between raw and cooked (boiled, drained) preparation, because cooking can slightly reduce the fiber content per gram due to water absorption.
After entering your values, click the Calculate Fiber button. The result will show the total dietary fiber in grams, along with a step-by-step breakdown of the calculation. Use the preset quick-fill buttons for common serving sizes like 85 g (3 oz) or 150 g (1 cup). The Reset button clears all fields and results.
Formula Explained
The calculation is based on standard USDA nutrition data for each choy variety. The formula is:
Fiber (g) = (Weight in grams / 100) × Fiber per 100g
Where Fiber per 100g is a constant derived from USDA food composition databases. For example, raw bok choy contains approximately 1.0 g of dietary fiber per 100 g. If you have 200 g of raw bok choy, the calculation is (200 / 100) × 1.0 = 2.0 g of fiber.
For cooked choy, the fiber density is slightly lower because the vegetable absorbs water during boiling, increasing its weight without adding fiber. For instance, cooked bok choy has about 0.8 g of fiber per 100 g. The calculator automatically applies the correct value based on your preparation selection.
Worked Examples
Example 1: You have 150 g of raw baby bok choy. Select "Baby Bok Choy" and "Raw". Enter 150 in the amount field with unit "g". The calculator computes: (150 / 100) × 1.2 = 1.80 g of fiber.
Example 2: You have 1 cup of cooked napa cabbage (about 70 g). Select "Napa Cabbage" and "Cooked". Enter 1 with unit "cups". The calculator converts 1 cup to 70 g, then computes: (70 / 100) × 1.0 = 0.70 g of fiber.
Example 3: You have 4 oz of raw choy sum. Select "Choy Sum" and "Raw". Enter 4 with unit "oz". The calculator converts 4 oz to 113.4 g, then computes: (113.4 / 100) × 1.5 = 1.70 g of fiber.
Tips for Accurate Results
- Weigh your choy on a kitchen scale for the most accurate fiber estimate. Volume measurements (cups) are approximate — a cup of loosely packed chopped choy weighs less than a tightly packed cup.
- If you are using frozen choy, note that the fiber content is similar to raw, but the weight may vary due to ice content. Thaw and drain before measuring for best accuracy.
- For stir-fried or sautéed choy, the fiber content per gram is similar to raw because the water loss concentrates the fiber slightly. However, if oil is added, the total weight increases without adding fiber, so the fiber percentage per gram decreases. This calculator does not account for added oil.
Frequently Asked Questions
Is choy high in fiber?
Choy is a moderate source of dietary fiber. A 100 g serving of raw bok choy provides about 1.0 g of fiber, which is roughly 4% of the daily recommended intake (25 g for women, 38 g for men). While not as high as legumes or whole grains, choy contributes to your overall fiber intake, especially when eaten in larger portions.
Does cooking destroy fiber?
Cooking does not destroy dietary fiber, but it can change the fiber's solubility and the vegetable's weight. Boiling causes choy to absorb water, so the fiber per gram decreases. However, the total fiber in the original vegetable remains the same — you are just eating more water weight. Our calculator accounts for this by using separate fiber densities for raw and cooked choy.
Can I use this calculator for other leafy greens?
This calculator is specifically calibrated for the choy varieties listed. For other greens like spinach, kale, or Swiss chard, the fiber content differs. You can find dedicated calculators for those on our site, such as the Avocado Fiber Calculator or the Kiwi Fiber Calculator.
What about the fiber in the stems vs. leaves?
The stems of choy (the white or pale green parts) contain slightly more fiber than the leaves. Our values are averages for the whole vegetable as typically consumed. If you are eating only stems or only leaves, the fiber content may vary by about 0.2–0.3 g per 100 g.
Reference Data
| Choy Variety | Fiber per 100g (Raw) | Fiber per 100g (Cooked) |
|---|---|---|
| Bok Choy (Pak Choi) | 1.0 g | 0.8 g |
| Baby Bok Choy | 1.2 g | 1.0 g |
| Choy Sum | 1.5 g | 1.2 g |
| Napa Cabbage | 1.2 g | 1.0 g |
Data sourced from the USDA FoodData Central database. For more detailed nutritional information, visit the USDA FoodData Central website.