78 kcal per Large Egg, Zero Added Fat — The Only Common Egg Preparation Where Every Calorie Comes from the Egg Itself
A large hard-boiled egg (~50g) has 78 calories, 6.3g protein, 5.3g fat, and 0.6g carbs. At 155 kcal per 100g, boiled eggs sit in the middle of egg preparations — lower than fried (196 kcal) but slightly higher than scrambled (149 kcal). The key distinction: every calorie in a boiled egg comes from the egg itself. No butter, no oil, no milk — just the egg cooked in its shell [1][2].
This zero-added-fat property makes boiled eggs the most predictable egg preparation for nutrition tracking. Scrambled eggs vary by 40+ kcal per 100g depending on butter and dairy additions. Fried eggs absorb different amounts of oil depending on pan temperature and oil quantity. Boiled eggs are one egg = one set of numbers, every time [1].
The apparent paradox — boiled eggs have more calories per 100g (155) than scrambled (149) despite no added fat — is explained by dilution. Scrambled eggs include butter and milk, which add weight faster than they add calories. A 50g egg becomes ~61g when scrambled (with dairy additions) but stays at ~50g when boiled. The boiled egg is more concentrated per gram [1].
294mg Choline per 100g (53% DV) — More Than Any Other Egg Preparation Except Fried
Hard-boiled eggs deliver 294mg choline per 100g (53% DV) — the second-highest among common egg preparations, behind only fried eggs (317mg). A single large egg provides 147mg choline (27% DV); two eggs deliver 294mg (53% DV). The adequate intake for choline is 550mg/day, and eggs are the most concentrated common food source [1][2].
The reason boiled eggs have more choline per 100g than scrambled (225mg) or omelette (235mg) is, again, concentration. Boiled eggs contain nothing but egg. Scrambled and omelette preparations dilute the egg mass with butter, milk, and cream — the choline amount per egg is similar, but the total weight increases, reducing per-100g density [1].
Soft-boiled eggs have approximately 290mg choline per 100g — almost identical to hard-boiled. The shorter cooking time doesn't significantly affect choline content. Choline is heat-stable in the yolk's phospholipid structures, so the difference between a 6-minute soft boil and a 12-minute hard boil has minimal impact on this nutrient [1][3].
30.7mcg Selenium (56% DV) and 1.11mcg B12 (46% DV) — The Micronutrient Density of an Unmodified Egg
Hard-boiled eggs provide 30.7mcg selenium per 100g (56% DV) — the highest selenium concentration among egg preparations (fried: 33.1mcg, but that includes selenium from cooking oil). Per large egg (~50g): 15.4mcg selenium (28% DV). Two eggs cover more than half the daily selenium requirement at just 155 calories [1].
Vitamin B12 at 1.11mcg per 100g (46% DV) makes boiled eggs a meaningful B12 source — two eggs provide 1.11mcg (46% DV). Vitamin D at 2.2mcg per 100g (11% DV), vitamin A at 149mcg RAE (17% DV), phosphorus at 172mg (14% DV), and riboflavin at 0.51mg (39% DV) round out a dense micronutrient profile for a 78-calorie food [1][2].
Iron at 1.19mg per 100g provides a modest contribution — less than fried eggs (1.89mg) because frying in iron-enriched oil can increase iron content. The iron in boiled eggs is entirely from the yolk's natural iron stores and is in a form (non-heme) that the body absorbs at lower rates than heme iron from meat. Two eggs provide about 1.2mg iron (7% DV) [1].
Hard-Boiled vs Soft-Boiled: 155 kcal vs 146 kcal — A 6% Difference That's Mostly About Water Retention
Hard-boiled eggs (155 kcal/100g) and soft-boiled (approximately 146 kcal/100g) differ by about 6%. The hard-boiled egg loses slightly more moisture during the longer cooking time (12 min vs 6 min), concentrating the nutrients slightly. The actual food content — protein, fat, vitamins — is nearly identical between the two cooking times [1][3].
The nutritional differences are minimal: protein 12.6g vs 12.0g, fat 10.6g vs 9.9g, cholesterol 373mg vs 370mg per 100g. Vitamin A is marginally higher in soft-boiled (155mcg vs 149mcg RAE) because shorter cooking preserves slightly more of the heat-sensitive retinol, but the difference is within normal variation between individual eggs [1].
For practical nutrition journaling, hard-boiled and soft-boiled can be logged as the same food — the differences are smaller than the natural variation between eggs from different hens, fed different diets, at different sizes. The choice between them is about texture preference (firm yolk vs runny yolk), not nutrition [1][3].
Boiled Egg vs. Other Egg Preparations (per 100g)
| Nutrient | Hard-Boiled | Soft-Boiled | Scrambled | Fried | Omelette |
|---|---|---|---|---|---|
| Calories (kcal) | 155 | 146 | 149 | 196 | 154 |
| Protein (g) | 12.6 | 12.0 | 10.7 | 13.6 | 10.6 |
| Total Fat (g) | 10.6 | 9.9 | 11.0 | 14.8 | 11.7 |
| Cholesterol (mg) | 373 | 370 | 289 | 401 | 310 |
| Choline (mg) | 294 | 290 | 225 | 317 | 235 |
| Selenium (mcg) | 30.7 | 29.5 | 22.5 | 33.1 | 25 |
| Vitamin B12 (mcg) | 1.11 | 1.15 | 0.76 | 0.97 | 0.8 |
| Sodium (mg) | 124 | 130 | 145 | 207 | 155 |
Practical Tips for Boiled Egg
- 1
Boiled eggs have zero added cooking fat — the 10.6g fat per 100g is entirely from the egg yolk. This makes calorie tracking perfectly predictable: 1 large egg = 78 kcal, 2 = 155, 3 = 233. No variation from butter or oil [1].
- 2
Choline at 294mg per 100g (53% DV) makes 2 boiled eggs the most efficient choline source per calorie among common egg preparations — 294mg at 155 calories. Scrambled provides 225mg at 149 kcal (less choline despite similar calories, due to dairy dilution) [1][2].
- 3
Hard-boiled vs soft-boiled differs by ~6% in calories (155 vs 146 kcal) — this is within normal egg-to-egg variation. Log them identically for practical nutrition tracking. The texture difference is culinary, not nutritional [1].
- 4
Selenium at 15.4mcg per large egg (28% DV) means 2 boiled eggs cover 56% of daily selenium — one of the highest selenium-to-calorie ratios among common foods. This selenium is naturally present in the egg, not from fortification [1].
- 5
A boiled egg is 78 kcal with 6.3g protein — the protein-to-calorie ratio (8.1g per 100 kcal) is the highest among whole-egg preparations. Fried egg has 6.9g per 100 kcal (lower because oil adds calories). Only egg-white preparations beat this ratio [1].
Frequently Asked Questions — Boiled Egg
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Important Notice
Nutritional values are based on USDA FoodData Central data for hard-boiled egg (whole, cooked). Soft-boiled values are estimated from hard-boiled data with adjustments for shorter cooking time and moisture retention. Actual nutrient content varies by egg size (medium ~44g, large ~50g, extra-large ~56g), hen diet, and production system. This tool is for informational and nutrition journaling purposes only — it is not a substitute for guidance from a qualified nutrition professional.
About the Author
Certified fitness professional and nutrition researcher with over 10 years of experience in the fitness and wellness industry. Founder of Food Nutrify, dedicated to making accurate, science-backed nutrition data accessible to everyone through free, easy-to-use calculators.
References & Sources
- [1] USDA FoodData Central (2024). Egg, whole, cooked, hard-boiled (FDC 173424). U.S. Department of Agriculture, Agricultural Research Service.
- [2] Puglisi MJ, Fernandez ML (2022). The Health Benefits of Egg Protein. PMC — Nutrients.
- [3] Réhault-Godbert S, Guyot N, Nys Y (2019). The Golden Egg: Nutritional Value, Bioactivities, and Emerging Benefits for Human Health. ResearchGate — Nutrients.