Portion logging
Flank is a practical steak reference for portion logging, especially when you want one stable raw baseline for single servings and larger sliced portions.
Informational journaling tool
Beef Flank Nutrition Calculator
Log flank steak calories, protein, fat, iron, zinc, sodium, and potassium from one stable raw flank reference, then use the same baseline for cooked-weight planning and batch meal prep.
164 cal
Per 100g raw
Shared raw flank reference
20.1g protein
Per 100g raw
Shared flank reference
9.4g fat
Per 100g raw
Source-backed total fat baseline
1.83mg iron
Per 100g raw
Total iron for cut comparison
Customize your portion
Use one shared raw flank reference with exact weight entry.
grams
Cooked-weight estimate
150g raw -> 122g cooked (19% moisture-loss planning estimate)
Nutrition facts
USDA raw choice flank reference scaled to your portion
Calories
12% DV
246kcal
USDA Atwater General energy
Protein
60% DV
30.2g
1.23g per 10 cal
Total fat
18% DV
14.1g
5.30g saturated fat
Iron
15% DV
2.75mg
USDA total iron reference
Iron context
The calculator logs total iron for the selected portion. Beef contains both heme and non-heme iron, but this page keeps total iron as the main tracked value instead of modeling personalized absorption.
Zinc
8.34mg76%
Sodium
77mg3%
Potassium
498mg11%
Phosphorus
251mg20%
Batch prep planner
Split a larger raw flank steak batch into even servings.
grams raw
meals
Batch prep note
Batch prep assumes plain beef and even division after cooking. Marinade, sauces, and finishing fats are intentionally excluded.
Total raw
907g
Total cooked
735g
Per serving raw
227g
Per serving cooked
184g
Per serving calories
372kcal
Per serving protein
45.6g
Per serving fat
21.3g
Per serving iron
4.1mg
Slice against the grain
Flank steak is usually easier to eat when you cut across the long muscle fibers after cooking and resting.
Cooking behavior
Flank loses moisture during cooking and is often prepared as a larger slab, so cooked-weight planning and portion division matter more than cosmetic cooking-mode choices.
Cut comparison
Flank is usually leaner than skirt steak and richer than ultra-lean sirloin references, which makes it a useful comparison point for sliced steak meals and batch prep.
Data & Methodology
The flank page uses one raw baseline for both single portions and batch-prep planning.
Main baseline
The calculator uses USDA FoodData Central entry 2646175 for raw boneless choice flank steak. Public calories use the record's Atwater General energy value of 164 kcal per 100g, while the same record also lists an Atwater Specific energy value around 170 kcal.
Cooked-weight estimate
Raw-to-cooked translation uses doneness-based shrinkage as a planning estimate based on USDA cooking-yield references for comparable steak cuts. It is a practical kitchen reference, not a lab-measured flank result for every grill or pan setup.
Excluded context
Restaurant finishing fats, sauces, and marinade retention can change the final total. They stay out of the calculator because there is no single reliable rule that fits every recipe.
Last reviewed: March 2026. This tool is for informational and journaling use only. It logs total iron and does not attempt personalized retention or absorption outputs.
The Nutritional Power of Flank Steak
Flank steak is a highly distinctive, intensely beefy cut that has become a staple in fitness and meal-prep communities. Originating from the abdominal muscles of the cow, flank is a hard-working muscle, which translates to a very lean profile with prominent, coarse muscle fibers. Nutritionally, flank steak is a powerhouse: a standard 100g raw portion provides approximately 192 calories, a massive 28 grams of protein, and only about 8 grams of fat. This makes it an incredibly efficient way to hit high protein targets without consuming excess calories.
In addition to its excellent macronutrient breakdown, flank steak is rich in essential vitamins and minerals. It is particularly noted for its high concentration of bioavailable heme iron and zinc, which are vital for oxygen transport and immune health. Because of its lean nature and strong muscle fibers, flank steak requires specific cooking and slicing techniques to ensure tenderness. It takes well to acidic marinades, which help break down the tough fibers, and it should always be cooked quickly over high heat and sliced thinly across the grain.
Flank steak's uniform shape makes it incredibly easy to portion out for weekly meal prep. Whether it's used in fajitas, stir-fries, or served over a vibrant salad, its robust flavor stands up well to strong spices and sauces. Our calculator allows you to input your exact raw or cooked weight, adjusting for the moisture loss that occurs during high-heat cooking, ensuring your macro tracking remains as precise as your meal planning.
Frequently asked questions
How many calories are in flank steak?
This page uses one raw USDA choice flank steak reference that lands around 164 calories per 100g, with totals scaling from that baseline.
How much protein is in 6 oz or 8 oz flank steak?
The calculator scales from the same raw USDA baseline, so 6 oz and 8 oz portions update automatically for protein, calories, fat, and key minerals.
Why do raw and cooked flank weights differ?
Cooking reduces moisture, so the cooked portion usually weighs less than the raw portion even when the total nutrients come from the same starting meat weight.
How should I log batch-cooked flank or carne asada-style portions?
Use the batch prep section with the total raw batch weight and the number of servings. It estimates the total cooked weight and the per-serving nutrition from the same plain-beef baseline.
Flank vs skirt steak: which one is leaner?
Flank steak is usually leaner than skirt steak. Skirt often runs higher in fat and calories, so it is worth checking the cut label before logging.
Why is marinade not included in the calculator?
Marinade retention varies by recipe, time, and cooking method, so this page keeps the calculator focused on plain beef reference values instead of applying one guessed absorption rule.
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