Steak Protein Calculator

A 12 oz steak is one of the most-Googled portion sizes because it's the classic American restaurant cut — and the answer most people want is simple: roughly 75–90 g of protein cooked, depending on the cut. A leaner 12 oz top sirloin lands closer to 90 g, while a fattier 12 oz ribeye sits around 75–82 g because marbling displaces some lean tissue. Either way, that’s more than the average adult needs in a single sitting (most nutrition guidelines suggest 25–40 g of protein per meal).

But '12 oz' is just an example. This calculator works for any steak weight you punch in — a 4 oz lunch portion, a 6 oz filet, an 8 oz sirloin, a 16 oz tomahawk, or a metric 250 g cut. It also accounts for the cut you choose (lean cuts pack ~8 g protein per cooked oz, fattier cuts ~7 g) and whether you entered the raw weight or the cooked weight. Raw beef loses about 25% of its weight during cooking, which concentrates the protein.

Cooking method matters mostly for calories, not protein. Grilling and broiling add roughly 0 extra calories. Pan-searing in oil or butter can add 50–150 calories per serving depending on how much fat ends up in the meat. The calculator estimates total protein in grams, total calories, protein per ounce, and how your steak stacks up against a typical 150 lb adult's daily protein target (~110 g at 1.6 g/kg).

How it works: Enter your steak's weight, pick the cut, tell us if the weight is raw or cooked, and choose your cooking method. We apply USDA-style protein density values (per 100 g) for each cut, adjust for cooking yield, and calculate total protein, calories, and per-ounce density in real time.

How Much Protein Is in a Steak? Cut-by-Cut Reference

Protein content depends mostly on weight and cut, with cooking method affecting calories more than protein. Below are reference tables and methodology so you can sanity-check any steak portion — whether it’s the popular 12 oz example or anything from a 4 oz appetizer to a 32 oz tomahawk.

Quick steak protein reference (cooked weight)

12 oz steak: raw vs. cooked, protein & calories

Why a 12 oz steak doesn’t have ‘exactly’ 12 oz of meat protein

When a menu says '12 oz ribeye,' that's almost always the raw, pre-cook weight. Beef typically loses 20–30% of its mass during cooking — water evaporates and rendered fat drips off. A 12 oz raw ribeye usually ends up around 8.5–9 oz on the plate. The protein, however, stays almost entirely in the meat. So while the cooked steak is lighter, it’s actually denser in protein per ounce. That’s why a 12 oz raw steak still delivers 70–90 g of protein even though the plate weighs less.

Lean cuts vs. marbled cuts: protein per ounce

Lean cuts like top sirloin, eye of round, flank, and filet mignon hover around 30–31 g of protein per 100 g cooked, or roughly 8.5 g per ounce. Marbled cuts like ribeye, T-bone, and porterhouse drop to about 25–26 g per 100 g (~7 g per oz) because the intramuscular fat takes up volume that would otherwise be lean muscle. The trade-off: marbled cuts taste richer and contain more calories — a 12 oz ribeye runs ~850 calories vs. ~550 for a 12 oz top sirloin.

Does cooking method change protein?

Protein is heat-stable for normal cooking temperatures. Grilling, pan-searing, broiling, sous vide, and even well-done cooking don't meaningfully reduce protein content — the amino acids stay in the meat. What changes is weight (more shrinkage at higher doneness) and calories (added oils, butter, marinades). A grilled 12 oz ribeye and a butter-basted 12 oz ribeye have nearly identical protein (~80 g), but the butter version can add 120+ calories of fat.

How much protein do you actually need?

Daily protein needs vary by body weight and activity. The basic RDA is 0.8 g per kg of body weight (about 55 g for a 150 lb adult), but most performance and longevity research now suggests 1.2–2.2 g/kg for active people. That puts a typical target between 80 g and 165 g per day. A 12 oz steak alone provides 70–90 g, which is half to all of a typical daily target in one sitting — generous, but not excessive for athletes or people on high-protein diets.

12 oz steak vs. other protein sources

For comparison: a 12 oz cooked chicken breast has about 100 g of protein and 540 calories. A 12 oz cooked salmon fillet has ~75 g protein and ~720 calories. A dozen eggs deliver ~72 g protein and ~840 calories. Per gram of protein, lean steak and chicken are the most efficient; salmon and eggs add valuable fats. Steak is also one of the best sources of heme iron, zinc, and B12, which plant proteins can’t match without supplementation.

Raw vs. cooked weight: which one should you enter?

If you're estimating from a restaurant menu or grocery store label, enter the raw weight — that's how steaks are sold. If you weighed your steak on a kitchen scale after cooking, enter the cooked weight. The calculator adjusts the protein density accordingly: raw steak is about 22 g protein per 100 g, while cooked steak is 25–31 g per 100 g because the water has been driven off. Using the wrong setting can swing your protein estimate by 25%.

Practical tips for hitting your protein target

If you’re aiming for 120–160 g of protein daily, a single steak can do a lot of the heavy lifting but shouldn’t be the only source — variety helps with micronutrients and reduces saturated fat intake. A common pattern is 30–40 g of protein at breakfast (eggs, Greek yogurt), 30–40 g at lunch (chicken, fish, legumes), and a 6–10 oz steak (45–80 g) at dinner. Spreading protein evenly across 3–4 meals is more efficient for muscle protein synthesis than loading it all into one giant steak dinner.

How This Calculator Works: Methodology & Parameter Explanations

Core formula: total_protein_g = cooked_weight_g × (protein_per_100g_cooked / 100); total_calories = cooked_weight_g × (calories_per_100g_cooked / 100) + cooking_fat_calories. If you entered raw weight, cooked_weight_g = raw_weight_g × (1 − shrinkage), where shrinkage is 25% by default and 30% for well done.

Parameter explanations

Assumptions

The 12 oz example value is illustrative only — the calculator works for any weight from 1 oz to 64 oz (or grams equivalent).

Protein densities are based on USDA-style averages for cooked beef: ribeye ~25 g/100 g, top sirloin ~30 g/100 g, filet mignon ~28.5 g/100 g, NY strip ~26.5 g/100 g, flank ~29.5 g/100 g, eye of round ~31 g/100 g.

Default cooking shrinkage is 25% (medium); well done uses 30%. Sous vide or rare cooking may shrink less (~15–20%).

Calories from added cooking fat are estimates: ~80 cal for oil, ~120 cal for butter. Actual values depend on how much fat is absorbed vs. left in the pan.

Estimates do not include sauces, marinades, butter compounds, or sides — only the steak itself plus cooking fat.

Parameter meanings