Sizu Riatto
Vegan Meal Prep Math · Chapter 7

Cost per 20 g of Protein

Price per gram ÷ protein per gram × 20. One line per food, and the cheapest protein in the shop is at the top.

Home › Calculators › Cost per 20 g of Protein

Opens on the book's Freezer Month. Change any number to your own and press Calculate.

A. Foods: protein per 100 g (FDC, or the label: protein ÷ serving × 100), the pack price and size

B. Recipes: food cost and protein a portion

Enter the foods and prices, then press Calculate.

The formula

  • Price per kg = pack price ÷ pack weight in kg (1 lb = 0.4536 kg; 1 oz = 28.35 g)
  • Grams of food that carry 20 g of protein = 20 ÷ (protein per 100 g ÷ 100)
  • Cost per 20 g of protein = those grams ÷ 1000 × price per kg
  • A recipe: food cost a portion ÷ protein a portion × 20
The book's worked example, Chapter 7. Dried lentils and beans lead: black beans at 1.69 a pound carry 20 g of protein for about 0.34; extra-firm tofu about 1.51. The five recipes run from 0.93 (the soup) to 1.33 (the burritos) per 20 g of protein, everything in the box counted.
Check it. Take one food: grams for 20 g of protein × price per gram. A food with half the protein needs twice the grams.

Honest limits. Cheap protein can come with a lot of calories (peanut butter) or very little else: these are just the numbers, not diet advice. A ready meal's protein is on its label: protein per serving ÷ the serving's grams × 100 gives its protein per 100 g. Prices are illustrative US prices from November 2026, shown without a currency sign; put in your own. Everything stays in your browser: no sign-up, nothing stored.

These calculators go with Vegan Meal Prep Math (Craft & Studio, Book 4), where every number on this page is worked by hand.