ProteinP:E Ratio Calculator
The protein-to-energy ratio ranks a food by how much protein it delivers relative to the fat and carbohydrate energy that comes with it. Enter the macros of any food or whole meal below.
Macros per serving
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P:E Ratio
proteinpercent.comProtein-dominant — at or above 50% of calories from protein.
- Vector angle
- 80.2°
- Gram ratio
- 8.65
Percentages are of calories, with fiber counted at half its carbohydrate weight — the same convention proteinpercent.com uses. A quotient of 1.0 corresponds to 40% of calories from protein.
How the ratio works
Protein content alone does not tell you much. Peanut butter has 25 g of protein per 100 g, which sounds excellent until you notice the 50 g of fat carrying 450 calories alongside it. The P:E ratio puts protein in the denominator's context: everything else the food makes you eat to get it.
quotient = 1.5 × protein ÷ (fat × 9/4 + carbohydrate − fiber/2) vector angle = arctan(quotient) in degrees
Two details are easy to get wrong. Fiber is discounted by half, not netted out completely, so it contributes about 2 kcal/g rather than 0 — this is not the usual “net carbs” convention. And the 1.5 is a scaling constant rather than physics: it exists so that a quotient of 1.0 lands on exactly 40% of calories from protein, which is the target the P:E approach is built around.
Reading the number
| Quotient | Angle | Means |
|---|---|---|
| 1.5+ | 56°+ | Protein-dominant. Half or more of calories from protein. |
| 1.0–1.5 | 45–56° | On target. At least 40% of calories from protein. |
| 0.5–1.0 | 27–45° | Middling. Protein present, but energy dominates. |
| Below 0.5 | Under 27° | Energy-dominant. Fat and carbohydrate crowd protein out. |
Frequently asked questions
- What is a good protein to calorie ratio?
- A P:E quotient of 1.0 or above is the usual target, which corresponds to 40% of calories coming from protein. Chicken breast, white fish, egg whites and non-fat Greek yoghurt all sit well above 1.0. Nuts, oils and most baked goods sit far below it.
- How is the P:E ratio calculated?
- Protein grams are divided by non-protein energy expressed in carbohydrate-gram-equivalents: 1.5 × protein ÷ (fat × 9/4 + carbohydrate − fiber/2). Fiber is discounted by half rather than subtracted entirely. The 1.5 multiplier places a quotient of 1.0 at exactly 40% of calories from protein.
- Which foods have the highest protein to calorie ratio?
- Lean animal proteins dominate: egg white, cod, haddock, tuna in water, shrimp, chicken breast, turkey breast, and non-fat Greek yoghurt or cottage cheese. Among plants, seitan, textured soy protein and tofu rank highest, though they carry more carbohydrate energy than lean meat does.
- What is the nutritional vector angle?
- It is the P:E quotient expressed as an angle — the arctangent of the quotient in degrees. A quotient of 1.0 becomes 45°, so anything above 45° is protein-dominant and anything below is energy-dominant. It makes the same number easier to read at a glance.
To score real ingredients automatically instead of typing macros, use the food tracker, or work out your daily target first with the protein calculator.