Purpose and steps
Calculates protein from body weight, subtracts protein and net-carbohydrate calories, and assigns the remaining calories to fat.
- Choose units and use the pre-pregnancy, resting or current measurements requested by the tool; keep observation dates consistent.
- Prepare Weight, Daily calorie target, Protein per kg of body weight, Daily net carbohydrates. Defaults demonstrate the model rather than your personal circumstances.
- Check the headline result and its components. A key interpretation for this tool is: The three macro calorie totals should add back to the entered calorie target.
- Compare the baseline with a changed scenario: Changing protein or carb targets automatically changes the remaining fat allowance.
Input reference and units
These values reproduce the model’s demonstration. Replace them with your own records or measurements; they are not recommended targets.
On a small screen, swipe the table horizontally to see all columns.
| Parameter | Demonstration value | How to enter it |
|---|---|---|
| Weight | 70 kg | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
| Daily calorie target | 2000 kcal | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
| Protein per kg of body weight | 1.6 g/kg | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
| Daily net carbohydrates | 30 g | Use the definition shown in the field label; keep this assumption consistent when comparing scenarios. |
Model-specific method
How this calculator produces its result
Protein grams = body weight in kg × selected protein rate. Protein and net carbs use 4 kcal/g; remaining calories are assigned to fat at 9 kcal/g.
Energy bookkeeping and weighted allocation
Energy allocation is a weighted sum because grams of protein, carbohydrate and fat have different modeled energy densities. Subtract the energy already assigned before converting the remainder into another nutrient. Dividing remaining calories by four rather than nine would miscalculate fat grams.
A static deficit or surplus is a budgeting estimate rather than a linear prediction of body-weight change. Expenditure can adapt, measurement is imperfect and changes in water and lean tissue affect weight. Activity factors can already include exercise; adding it again may double-count energy use.
TDEE ≈ estimated resting energy × activity factor Energy from macros = 4 × protein grams + 4 × carb grams + 9 × fat grams Planned balance = intake − estimated expenditure
- kcal: energy, not food mass
- g: grams of the selected macronutrient
- Activity factor: empirical multiplier, not measured exercise energy
- Balance: model estimate over the specified period
Worked example
At 70 kg, 2,000 kcal, 1.6 g/kg protein, and 30 g net carbs: protein is 112 g, carbs are 30 g, and remaining fat is about 159 g.
Reproduce the default scenario
This is a separate example, calculated using the exact engine on the tool page and the defaults in the input reference above. Health examples use metric units. Displayed rounding may differ from intermediate precision.
- Daily fat
- 159 g
- Daily protein
- 112 g
- Daily net carbohydrates
- 30 g
- Calories from fat
- 72%
Reading results without overstating them
- The three macro calorie totals should add back to the entered calorie target.
- Changing protein or carb targets automatically changes the remaining fat allowance.
Assumptions and exclusions
- Net-carbohydrate labeling varies and is not defined identically for every food.
- The tool does not assess micronutrients, fiber quality, medications, or whether keto is appropriate.
Sources and content notes
Toolify describes the implemented algorithm and its assumptions. Sources below support the topic or applicable rules; they do not endorse this calculator. Examples are illustrative, and published rules take precedence over simplified estimates.
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