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Body measurements and macro planning choices
Enter 15–90 completed years.
years
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Choose a 0–25% calorie adjustment.
Choose 2–6 meal slots.
meals
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Mifflin works from standard measurements; lean-mass formulas also need body fat.
Leave blank for Mifflin, or enter 3–70% for a lean-mass path.
%
Keep 0 for the selected profile, or enter a floor up to 5 in the chosen basis.
Leave blank for the selected profile, or enter three percentages totaling 100.
This changes meal rows only; daily calories and macro totals stay fixed.
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MealCaloriesProteinCarbsFatCopy
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How to use this starting point

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These are planning estimates, not medical nutrition therapy. Energy needs and scale response vary; adolescents, pregnant people, anyone managing a clinical condition, and anyone recovering from disordered eating should review changes with a qualified clinician or dietitian.

Introduction

A macro target begins with an estimate of daily energy needs, then divides that energy among protein, carbohydrate, and fat. The calorie estimate sets the overall amount of food energy. The macro split describes where those calories come from, so two plans with the same calories can contain very different gram targets.

Resting energy is the starting point. Basal metabolic rate (BMR) estimates energy use at rest from body measurements or lean mass. An activity factor expands BMR into estimated maintenance energy, often called total daily energy expenditure (TDEE). A maintenance plan stays at that estimate, while a loss, recomposition, or gain plan applies a chosen percentage adjustment.

BMR
Estimated daily energy use at rest.
TDEE
Estimated maintenance energy after an activity multiplier is applied.
Macro ratio
The percentage of target calories assigned to protein, carbohydrate, and fat.
Protein floor
A minimum protein target based on body weight or estimated lean mass.

Protein and carbohydrate each provide 4 kilocalories per gram, while fat provides 9. That difference makes grams and calorie percentages easy to confuse. A 30% fat target does not mean 30% of the food's weight is fat, and equal gram amounts do not provide equal energy.

Planning choices that most affect calorie and macro targets
ChoiceWhat changesImportant limit
Energy formulaThe resting-energy estimateLean-mass formulas depend on a body-fat estimate
Activity profileEstimated maintenance caloriesJob and training activity are reduced to one multiplier
Goal paceThe deficit or surplus from maintenanceThe arithmetic does not predict individual weight change exactly
Macro profile or custom ratioCalories assigned to each macroThe percentages must total 100%
Meal patternDistribution across the dayDaily calories and macro totals stay unchanged

Predictive equations describe an average relationship, not a measured metabolism. Real energy needs vary with training, occupation, sleep, illness, medication, adaptive changes, and errors in food or activity records. A useful plan is reviewed against several weeks of weight trend, appetite, recovery, and performance rather than judged from one calculated day.

These targets are planning estimates, not medical nutrition therapy. Adolescents, pregnant people, anyone managing a clinical condition, and anyone recovering from disordered eating should review diet changes with a qualified clinician or dietitian.

How to Use This Tool:

Choose the energy equation first, because that determines which body measurements are required and how every later target is built.

  1. Enter formula sex, age, body weight, and height with the correct units.
  2. Select the activity profile and planning goal, then set a calorie adjustment from 0% to 25%.
  3. Choose Mifflin–St Jeor for a weight-and-height estimate, or enter body fat before using Katch–McArdle or Cunningham.
  4. Select a macro profile or enter a custom protein, carbohydrate, and fat ratio totaling 100%. Add a protein floor only when its body-weight or lean-mass basis is appropriate.
  5. Choose two to six meals and a meal pattern, then review Daily targets before using the meal allocation.
  6. Keep the same formula and activity profile when comparing check-ins. Change the plan only after observing a meaningful trend rather than reacting to one day's scale movement.

Interpreting Results:

Estimated maintenance is the modeled starting point, and Current daily target includes the goal adjustment. Macro grams are derived from that target, not independently chosen quantities. The weekly change figure is an energy-equivalent projection based on 7,700 kcal per kilogram, not a promise of scale change.

Meal rows are one arithmetic distribution of the daily totals. They do not prescribe meal timing, food selection, or nutrient quality. Compare the protein and fat grams per kilogram with the planning notes, but do not treat those cues as a diagnosis or a substitute for individualized advice.

If a protein floor raises the profile's protein share, carbohydrate and fat are reduced in their existing proportion. A floor that is already met leaves the selected ratio unchanged.

Technical Details:

Weight is normalized to kilograms and height to centimetres. Mifflin–St Jeor uses weight, height, age, and the selected formula-sex constant. Katch–McArdle and Cunningham use lean mass, calculated as body weight multiplied by one minus body-fat fraction.

Formula Core

The chosen resting-energy equation feeds maintenance energy, the goal adjustment, and finally macro grams.

BM=10W+6.25H-5A+s BK=370+21.6L BC=500+22L M=B×f T=M+gM Gx=Trx100ex

W is kilograms, H is centimetres, A is age, and s is 5 for the male formula or −161 for the female formula. L is lean mass in kilograms. f is the activity factor, g is the signed goal adjustment, rx is a macro's calorie percentage, and ex is 4 kcal/g for protein or carbohydrate and 9 kcal/g for fat.

For a 32-year-old female formula input at 70 kg and 170 cm, Mifflin–St Jeor gives 1,441.5 kcal/day. The lightly active factor of 1.375 gives 1,982.0625 kcal/day for maintenance. A balanced 30/40/30 split produces about 148.7 g protein, 198.2 g carbohydrate, and 66.1 g fat. Visible results are rounded only after the full-precision calculation.

Rule Core

Activity factors and goal adjustment rules
Planning choiceFactor or rule
Sedentary1.2 × BMR
Lightly active1.375 × BMR
Moderately active1.55 × BMR
Very active1.725 × BMR
High-volume athlete1.9 × BMR
MaintenanceNo goal adjustment
Fat lossSubtract the selected percentage of maintenance
RecompositionSubtract 60% of the selected percentage
Muscle gainAdd the selected percentage of maintenance
Built-in macro profile percentages
ProfileProteinCarbohydrateFat
Balanced30%40%30%
High protein35%35%30%
Lower carbohydrate35%25%40%
Endurance25%50%25%

A custom ratio accepts three non-negative percentages totaling 100 within 0.01 percentage point. A protein floor may use grams per kilogram or grams per pound of body weight or lean mass. It can only raise protein, is capped at 50% of target energy, and redistributes the remaining carbohydrate and fat proportionally. Lean-mass formulas and lean-mass protein floors require body fat from 3% to 70%.

Meal patterns normalize a set of relative weights so all meal shares sum to 1. Calories, carbohydrate, and fat follow those shares; protein is divided evenly across the selected two to six meals. The daily totals do not change.

Accuracy and Health Limits:

The calculation accepts ages 15 to 90, normalized weights from 40 to 250 kg, and heights from 130 to 220 cm. Those validation ranges prevent obvious unit errors; they do not establish that any equation is appropriate for a particular person.

  • Activity multipliers are broad categories and can overstate or understate maintenance energy.
  • Body-fat error directly changes lean-mass equations and lean-mass protein floors.
  • The 7,700 kcal/kg projection ignores water shifts and metabolic adaptation.
  • Food quality, micronutrients, allergies, medication, and clinical needs are outside the calculation.

References: