Both parts of an egg contain protein. In a large egg, the white provides about 3.6 grams of protein and the yolk adds another 2.7 grams, bringing the total to roughly 6.3 grams. That means the white holds about 57% of the egg’s protein while the yolk contributes the remaining 43%.
Protein in the Egg White
The egg white (albumen) is mostly water and protein, with almost no fat. That makes it one of the leanest protein sources available. The dominant protein is ovalbumin, which accounts for about 54% of all egg white protein. Another major one, ovomucoid, makes up around 11%. In total, dozens of distinct proteins have been identified in egg whites, but ovalbumin is the workhorse.
Because the white carries so little fat, its calorie-to-protein ratio is extremely efficient. A single large egg white has only about 17 calories for its 3.6 grams of protein. This is why bodybuilders and people watching their calorie intake often eat egg whites alone.
Protein in the Egg Yolk
The yolk is best known for its fat and cholesterol, but it still delivers 2.7 grams of protein per large egg. Researchers have identified over 300 distinct proteins in chicken egg yolk, many of which serve functions beyond simple nutrition. Yolk proteins include lipoproteins (proteins bound to fats), antibodies, and phosphorus-rich proteins that provide amino acids, minerals, and vitamins needed for embryonic development.
Some of these yolk proteins have shown anti-inflammatory and antioxidant properties in laboratory studies. So while the yolk is calorie-dense (around 55 calories versus the white’s 17), its protein comes packaged with fat-soluble vitamins like A, D, E, and K, plus minerals like iron and zinc that the white lacks almost entirely. Discarding the yolk saves calories but also removes a meaningful chunk of the egg’s total protein and most of its micronutrients.
Amino Acid Comparison
Protein quality depends on amino acids, not just grams. Eggs are considered a “complete” protein because they contain all nine essential amino acids your body can’t make on its own. Both the white and yolk contribute all nine, but in different amounts.
Based on USDA data for a single large egg, the white delivers more of every essential amino acid than the yolk does. The gap is especially wide for methionine (132 mg in the white vs. 64 mg in the yolk) and phenylalanine (226 mg vs. 116 mg). For leucine, the amino acid most closely linked to muscle building, the white provides 335 mg compared to the yolk’s 238 mg. Still, the yolk’s contribution is far from trivial. Eating whole eggs gives you a fuller amino acid profile than eating whites alone.
Cooking Changes How Much Protein You Absorb
Raw eggs are only about 65% digestible, meaning your body absorbs roughly two-thirds of the available protein. Cooking raises that figure to about 94%. Heat unfolds (denatures) the egg’s tightly coiled proteins, making them easier for digestive enzymes to break apart. So a cooked egg delivering 6.3 grams of protein gives your body close to 5.9 usable grams, while a raw egg of the same size would provide closer to 4.1 grams.
This applies to both the white and the yolk. Whether you scramble, poach, or hard-boil them, the improvement in digestibility is significant. Raw egg whites also contain a protein called avidin that binds to biotin (a B vitamin) and blocks its absorption. Cooking deactivates avidin, which is another reason cooked eggs are nutritionally superior.
Whole Eggs vs. Whites Only
If your goal is pure protein with minimal calories, egg whites are the clear winner. You can eat three egg whites for about 51 calories and 10.8 grams of protein. Three whole eggs would give you roughly 19 grams of protein but at around 215 calories.
But for general nutrition, whole eggs offer more value per serving. The yolk’s protein comes alongside nutrients that support brain health, bone density, and immune function. For most people who aren’t on a strict calorie budget, eating the whole egg means more total protein, a broader amino acid intake, and a much wider range of vitamins and minerals. The short answer: protein is in every part of the egg, and eating both parts together is the most nutritionally complete option.