The formula
Cost per 100 g of protein = pack price ÷ (servings in the pack × grams of protein per serving) × 100.
Worked example from our data: Grade A Large White Eggs (Kroger) at Kroger.com costs $1.78 for 18 ct. The label lists 18 servings at 6 g of protein, so the pack holds 108 g. $1.78 ÷ 108 g × 100 = $1.65 per 100 g of protein, the lowest of the 52 products we recorded (read Oct 26, 2026).
Steps
- Find protein per serving on the nutrition panel, not in the marketing text on the front.
- Find servings per pack. Labels sometimes say “about”; treat the figure as approximate.
- Multiply them for total protein in the pack.
- Divide price by that total, then multiply by 100 so the answer is per 100 g.
- Compare regular prices to regular prices. A sale price is a moment, so we label it and use the regular price when both are shown.
What the spread looks like
The cheapest product in each category, per 100 g of protein, in our data:
- EggsGrade A Large White Eggs$1.65
- Beans and lentilsLentil Beans (dry brown lentils)$1.87
- Other foodsCreamy Peanut Butter$2.34
- Meat and fishFrozen Raw Boneless Skinless Chicken Breasts$3.44
- Dairy2% Low Fat Small Curd Cottage Cheese$4.79
- Whey proteinGold Standard 100% Whey, Double Rich Chocolate$7.01
- Protein barsBuilders Chocolatey Peanut Butter 20g Protein Bars$9.16
- Plant proteinDark Chocolate Plant Protein Powder$10.00
Across all products the priciest costs 11.0 times the cheapest. See the live ranking with filters on protein per dollar.
Traps to avoid
- Pack size. Bigger is not automatically cheaper per gram.
- Protein is not the only thing in the pack. Cost per gram says nothing about calories, sugar, sodium or fibre.
- Quality. The US Dietary Guidelines for Americans 2025–2030 advise people to prioritise high-quality, nutrient-dense protein foods and to eat a variety of animal and plant sources (DGA 2025–2030, PDF). Cheapest per gram is a tie-breaker, not a diet.
- Regional prices. Retailers price by store and region, and rows say where a page gave a store context.
Next: work out how much protein you need and what it costs per day.