Nutrition
Macro Calculator
Convert a daily calorie target into protein, carbs, and fat grams based on your goal and split preference.
Result
Where the calories come from
Protein, carbs and fat as calories, adding up to the daily target.
What does the Macro Calculator calculate, and which formula does it use?
The Macro Calculator turns your TDEE and goal into daily protein, carb, and fat targets. It first scales calories — maintain ×1.0, cut ×0.85, bulk ×1.1 — then sets protein per bodyweight (1.8 g/kg maintaining, 2.2 cutting, 2.0 bulking), and splits the remaining calories into carbs and fat by your chosen ratio, counting 4 kcal per gram of protein or carbs and 9 per gram of fat.
Last updated .
How to use it
- Enter your maintenance calories (TDEE, from the TDEE Calculator) and body weight, then pick a goal and a split. The goal sets calories (maintain, cut 15%, bulk +10%) and protein per kg (1.8, 2.2 or 2.0 g); the split decides how the rest divides between carbs and fat, and the higher-protein split adds 0.3 g/kg of protein.
- Read the daily calorie target and the grams of protein, carbs and fat; the chart shows each as calories, adding up to the target.
- Carbohydrate timing improves training performance: concentrate 50–60% of your daily carbs around your training window (pre- and post-workout) if you train at moderate to high intensity.
- If full macro tracking feels overwhelming, start with protein only. Consistently hitting protein within 10% of target daily delivers roughly 80% of the benefit of complete macro tracking.
- Keep fat from falling too low: the calculator warns under 0.5 g per kg of body weight (about 0.23 g per lb). If a split or a deep cut pushes fat that low, pick a split with more fat or a smaller cut.
Questions people usually ask
Which formula is used here?
Uses goal-adjusted calorie targets, bodyweight-based protein ranges, and selected carb/fat split assumptions.
Can I use metric or imperial units?
Yes. This tool supports both metric and imperial units and remembers your preference.
Is this medical advice?
No. This tool provides general fitness estimates and should not replace medical guidance.
Is this tool free and private to use?
Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.
Do these tools replace medical guidance?
No. These outputs are general fitness estimates — not medical advice.
Can I switch between metric and imperial units?
Yes. Every tool supports both systems and remembers your preference in localStorage.
The formula, worked through
- Formula Macronutrient Ratio Formula
Macronutrient ratio formula: protein 1.6–2.2 g/kg, fat 0.6–1.0 g/kg (≥20% of calories), carbs = (total cal − protein·4 − fat·9) / 4.
- Formula Protein Intake Formula
protein_g = mass_kg × goal_factor. Goal factors: 0.8 sedentary (RDA), 1.6 trained baseline, 1.8 deficit / hypertrophy, 2.2 advanced cut or older lifter.
- Formula Macro Cycling Formula
Macro cycling formula: training days get +100 to +200 kcal and more carbs, rest days −300 to −500 kcal and more fat, with protein per kg of lean mass fixed all week.
Related calculators
- Nutrition TDEE Calculator
Estimate your daily energy expenditure with Mifflin-St Jeor + activity factors.
- Nutrition Protein Intake Calculator
Get daily protein targets based on training level and goal.
- Nutrition Intermittent Fasting Window Planner
Plan protocol-based eating and fasting windows with a 24-hour timeline and 5:2 day picker.
- Planning Calorie Deficit Calculator
Estimate required daily calorie deficit for a target timeline and bodyweight change.
Background on the Macro Calculator
- Guide How to Calculate Macros for Bulking: A Complete Guide
Calculate the right protein, carbs, and fat split for a lean bulk. Learn why a 200-300 calorie surplus is optimal, how much protein you actually need.
- Comparison Cutting vs Bulking: When to Do Each
Unravel the 'cutting' vs 'bulking' debate to plan body composition changes. Learn when to strategically focus on fat loss or muscle gain for peak fitness.
- Examples Macro Calculator Examples
Macro calculator examples for sedentary professionals, runners, lifters, and elite athletes. See real targets and how to adjust for your body and goal.
- Checklist Bulking Phase Checklist
Plan a structured bulking phase with this actionable checklist. Learn to optimize nutrition, training, and recovery for effective hypertrophy.
- Statistics Creatine Statistics: Effects on Strength, Power & Health
Evidence-based creatine statistics: strength gains, optimal dosing, safety profile, cognitive effects, and clinical applications from peer-reviewed.
- Learn What Is Glycogen? Simply Explained
Understand glycogen's role as the body's primary stored carbohydrate, fueling muscles and brain. Learn how it's formed, used, and impacts energy.
Articles
- 11 min read GLP-1 Muscle Loss: Keep Lean Mass with Lifting and Protein
GLP-1 weight loss costs lean mass: 25-39% of the total. How lifting 2-3x weekly and 1.2-1.6 g/kg protein hold muscle, and where the magnitude is debated.
- 13 min read Body Recomposition for Lifters: The Calorie Math
Body recomposition is real for specific populations under specific conditions. The four conditions, protein math scaled to LBM, 12-week example.
- 12 min read Protein for Muscle Gain: 1.6 g/kg (Morton 2018)
Morton 2018 placed the protein plateau at 1.6 g/kg with a 95% CI upper bound near 2.2 g/kg (49 studies, n=1,863). Cutting raises it to 2.3-3.1 g/kg lean.
By goal
Use it from code
The same calculation as a JavaScript module you can import. It runs where you import it, with no request, key or rate limit.
import { compute } from "https://aifithub.io/engines/macro-calculator.js";Input and output contract, TypeScript types and the guide for agents.