Your stir-fry isn’t usually sold by the slice, but if you press it into a pan, chill it, and cut it into meal-prep portions, slice-based nutrition becomes genuinely useful. This calculator takes the weight of your whole cooked batch and the number of slices you plan to cut, then works out calories and macros for each slice. It accepts your numbers directly from a food label or recipe tracker — either total batch calories or protein, carbs, and fat per 100 g.
Designed for meal preppers, home cooks, and anyone logging calories without weighing every bite, the tool handles the arithmetic so you can focus on portioning. It also shows the weight per slice and a full macro breakdown, making it easy to adjust your cut — four thick slices vs. six thinner ones — before you commit to a container.
Use the quick-fill presets for common stir-fry styles, or enter your own values from a recipe app, package label, or a USDA nutrition entry. The result updates with a clear breakdown, including the 4-4-9 math behind the estimate.
🍳 Stir-Fry Slice Calculator
Batch details
Macros per 100 g (only used when batch calories is blank)
📊 Results
Results appear here after you press Calculate.
How to Use the Stir-Fry Slice Calculator
Start by weighing your entire cooked stir-fry in the pan or bowl you’ll portion from. A digital kitchen scale and the pan’s tare function make this easy: place the pan on the scale, zero it, add the finished stir-fry, and record the total grams. Next, decide how many slices or portions you want and enter that number. Finally, enter either the whole batch’s calorie total (from a recipe builder or tracking app) or the protein, carbohydrate, and fat values per 100 g from the package label or an ingredient database. Leave batch calories blank if you want the calculator to estimate it from the macros using the 4-4-9 method.
Pro tip: Weigh the stir-fry after it has stopped steaming. Evaporated water changes the weight, and a sloppier measurement makes every slice’s calorie estimate less reliable.
How the Math Works
The calorie estimate rests on the Atwater general factors used in nutrition labeling: protein provides 4 kcal per gram, carbohydrates provide 4 kcal per gram, and fat provides 9 kcal per gram. The calculator first converts the macro values per 100 g into an energy density:
Energy per 100 g = (protein × 4) + (carbohydrates × 4) + (fat × 9) kcal
It then scales that density to the whole batch and divides by the number of slices:
Total batch calories = energy per 100 g × total weight ÷ 100
Calories per slice = total batch calories ÷ number of slices
The same scaling is applied to each macro individually, so you also get protein, carbs, and fat per slice. This method is the same one used by most recipe nutrition analyzers, and the underlying factors are published by the USDA and FDA. For a more detailed database of food values, you can search USDA FoodData Central.
Worked Examples
Example 1 — Chicken and vegetable stir-fry. Your pan holds 850 g of finished stir-fry and you plan to cut it into 6 equal slices. The label or recipe tracker shows 14 g protein, 9 g carbs, and 7 g fat per 100 g. Energy per 100 g = (14×4) + (9×4) + (7×9) = 56 + 36 + 63 = 155 kcal. Total batch = 155 × 850 ÷ 100 = 1318 kcal. Each slice = 1318 ÷ 6 ≈ 220 kcal, with a slice weight of 850 ÷ 6 ≈ 142 g and about 19.8 g protein, 12.7 g carbs, and 9.9 g fat.
Example 2 — Entering batch calories directly. A tofu and vegetable stir-fry logs 1,240 kcal for the whole recipe. You cut it into 4 large slices. Each slice is 1,240 ÷ 4 = 310 kcal. The slice weight depends on the total batch weight; if the pan holds 720 g, each slice weighs 180 g, and you can decide whether that fits your target serving size.
Tips for Consistent Portions
- Use a scale for the whole batch, not a measuring cup. Stir-fry ingredients pack differently depending on chop size and sauce, so weight is the most reproducible measure.
- Include all cooking oil and sauce. A tablespoon of oil adds roughly 120 kcal; leaving it out underestimates every slice. Measure oil as you add it, or split the bottle’s nutrition across the batch.
- Cut from one edge to the other in a straight line. If the stir-fry is pressed into a square or round pan, mark slices before cutting so the portions stay visually even.
- Weigh a couple of finished slices. If one slice is 20 g heavier than another, its calories will be proportionally higher. Adjust by weight, not by eye, when your calorie goal is tight.
- Update the calculator when ingredients change. Swapping chicken for beef or adding a peanut sauce changes both macros and total calories; re-run the numbers for each new batch.
Reference: Approximate Macros for Common Stir-Fries
Use these values as rough starting points when no label is available. Actual numbers vary with oil, sauces, and vegetable-to-protein ratio.
| Stir-fry style | Protein (g/100g) | Carbs (g/100g) | Fat (g/100g) | Approx. kcal/100g |
|---|---|---|---|---|
| Chicken & vegetable | 14 | 9 | 7 | 155 |
| Beef & broccoli | 12 | 8 | 10 | 170 |
| Tofu & mixed vegetables | 7 | 10 | 8 | 140 |
| Shrimp stir-fry | 15 | 8 | 5 | 137 |
| Pork & cabbage | 11 | 6 | 12 | 176 |
| Mushroom & eggplant | 5 | 8 | 9 | 133 |
For a broader per-100g reference across many stir-fry and protein-based dishes, see the stir-fry per-100g calorie calculator. If you are also tracking the protein side separately, a chicken nutrition calculator can help you compare raw ingredient options before they enter the wok.
Frequently Asked Questions
Does fiber count as carbs in this calculator? Yes. Standard nutrition labels already include fiber in the total carbohydrate value, and this tool uses the same 4 kcal per gram factor for all carbs. If you follow a net-carb approach, subtract fiber separately from the carb result; this calculator does not do net carbs.
What if my stir-fry isn’t actually sliced? You can still use the tool: treat “slices” as any equal portion, such as scoops from a pan or servings from a container. The math is identical as long as the total batch is divided evenly.
Why does my tracking app give a different number? Differences usually come from ingredient database entries, how cooked weight is measured, and whether oil or sauce was fully counted. The 4-4-9 method is an estimate, not a lab measurement, so expect small fluctuations between tools.
Can I use this for other sliceable dishes? Yes. The same calculation works for frittatas, lasagna, baked casseroles, and any dish you portion by slicing. Just enter that dish’s weight, slice count, and nutrition values.