Zone Diet Block Calculator
Work out your daily Zone diet blocks from weight, body fat and activity level — with protein, carbohydrate and fat grams and a split across three meals and two snacks.
How it works
Lean mass (lb) = weight × (1 − body fat %) ÷ 0.4536 · protein (g) = lean mass (lb) × activity factor (0.5–1.0) · blocks = protein ÷ 7, rounded · 1 block = 7 g protein + 9 g carbohydrate + 1.5 g added fat
Dr Barry Sears' Zone diet sets protein from lean body mass and activity, then builds every meal from “blocks” in a fixed 40:30:30 ratio of calories from carbohydrate, protein and fat. One block is 7 g of protein, 9 g of carbohydrate and 1.5 g of added fat (the extra fat assumes about 1.5 g already comes with the protein source), the convention also used in the CrossFit Journal Zone meal plans. Most people end up with 11–16 blocks a day, eaten as three meals and two one-block snacks.
Worked example
An 80 kg person with 20% body fat and light activity: lean mass = 64 kg = 141.1 lb; protein = 141.1 × 0.6 = 84.7 g; blocks = 84.7 ÷ 7 = 12.1 → 12 blocks per day: 84 g protein, 108 g carbohydrate and 18 g added fat, split 4 + 3 + 3 blocks for meals plus two 1-block snacks.
Sources: Sears B (1995) The Zone: A Dietary Road Map. HarperCollins · CrossFit Journal — Zone meal plans (2004)
Frequently asked questions
What is a Zone block?
A block is one unit of each macronutrient: 7 g protein, 9 g carbohydrate and 1.5 g added fat (some versions use 3 g when the protein is very lean). Every meal contains equal numbers of protein, carb and fat blocks.
How many blocks should I eat?
The number comes from your lean body mass and activity, as calculated here. Many Zone guides treat about 11 blocks as a minimum for women and 14 for men, and athletes often need 18 or more.
Why does body fat matter?
Protein needs scale with lean tissue, not total weight. Two people of the same weight but different body fat get different protein — and so block — targets.
Is the Zone diet the same as 40/30/30 macros?
Yes, in terms of calories: 9 g carbs (36 kcal), 7 g protein (28 kcal) and about 3 g total fat (27 kcal) per block give roughly 40% carbohydrate, 30% protein and 30% fat.
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This calculator gives general nutrition estimates for healthy adults and is not medical advice. People with diabetes, kidney disease, pregnancy or other conditions — and anyone using medication that affects blood sugar — should follow their doctor or dietitian.