Macro Calculator
Free macro calculator with a complete protein / carb / fat breakdown for cutting, maintenance and lean bulking. Protein-first (g/kg) approach, Mifflin-St Jeor and Katch-McArdle formulas, no signup.
Don't know your target? Use the calculator below.
Eat at maintenance — body-composition focused protein
A hormonal-health floor (0.5 g/kg or 20% of calories) is applied automatically.
Per-meal split
Related next steps
- Don't have a calorie target yet? Get a fuller breakdown with the Calorie Calculator.
- Planning to hit these macros within a fasting window? Find your schedule.
- Training toward a cut or bulk? Dial in your cardio zones with the Heart Rate Zone Calculator.
These are estimates for general fitness planning — not medical or clinical nutrition advice. If you have a medical condition (diabetes, kidney disease, an eating disorder history, or you're pregnant or nursing), talk to a registered dietitian or your doctor before making significant changes.
How to use
- 1
Type in your daily calorie target and body weight — or expand ‘I don't know my calorie target’ to compute one right here.
- 2
Pick a goal (cutting, maintenance or lean bulk). Your protein target auto-adjusts to a research-backed g/kg default you can still fine-tune.
- 3
Read the donut and macro cards for grams, calories, percentages and everyday food equivalences — no signup, no paywall.
Free Macro Calculator — Protein, Carbs & Fat for Cutting, Maintenance and Lean Bulking
A protein-first macro calculator that turns any daily calorie target into a complete gram-and-percentage breakdown of protein, carbs and fat — no signup, no email, no paywall.
Macros — short for macronutrients — are the three energy-providing nutrients in your diet: protein, carbohydrates and fat. Total calories tell you how much you're eating, but macros tell you what those calories are doing: protein preserves and builds muscle, fat supports hormone production and vitamin absorption, and carbs fuel training and recovery. Two people can eat the exact same calorie total and get very different physique and performance results depending on how those calories are split.
Most macro calculators lock you into a fixed percentage split — often 40% carbs, 30% protein, 30% fat — no matter your body weight or goal. The evidence-based sports-nutrition approach is different: set protein first as grams per kilogram of body weight, because protein needs scale with your lean tissue, not with your energy intake. Typical targets are around 2.2–2.4 g/kg when cutting (higher, to preserve muscle in a deficit), 1.6–2.0 g/kg at maintenance and 1.6–2.2 g/kg on a lean bulk. Fat is set next with a hormonal-health floor (roughly 0.5 g/kg, or about 20% of calories, whichever is greater), and whatever calories remain go to carbs.
This tool supports two BMR formulas. Mifflin-St Jeor is the modern default and tends to be the most accurate for the general population. Katch-McArdle uses your lean body mass instead of total weight, which makes it more accurate for lean or muscular individuals — so it's unlocked whenever you enter a body fat percentage. Being transparent about which formula you're using, and why, is a real trust and accuracy differentiator that most competitors quietly gloss over.
Compared to popular macro calculators, this one shows the full protein / carb / fat breakdown immediately — no account required, no email capture, no premium tier. You get grams, calories and percentages side by side, a color-coded donut chart, everyday food equivalences so the numbers feel tangible, an optional per-meal split, and a clear warning when your calorie target is too low for a sensible protein and fat combination. Everything runs in your browser and nothing is stored on our servers.
Frequently Asked Questions
What are macros?
Macros are the three macronutrients that provide calories: protein (4 kcal/g), carbohydrates (4 kcal/g) and fat (9 kcal/g). Tracking them tells you not just how much you're eating but what those calories are made of — which is what actually drives body-composition and performance changes.
How much protein do I need per day?
For active adults, common evidence-based targets are around 1.6–2.0 g per kg of body weight at maintenance, 2.2–2.4 g/kg while cutting to preserve muscle in a calorie deficit, and 1.6–2.2 g/kg on a lean bulk. This tool sets a research-backed default based on your goal and lets you fine-tune it.
What's the difference between Mifflin-St Jeor and Katch-McArdle?
Mifflin-St Jeor estimates your basal metabolic rate from age, sex, height and total weight. It's the modern default and works well for most people. Katch-McArdle uses your lean body mass instead of total weight (calculated from body fat percentage), which is more accurate for lean or muscular individuals whose fat mass isn't representative of their metabolic tissue.
Should I eat more protein when cutting?
Yes. In a calorie deficit, higher protein intake (roughly 2.2–2.4 g/kg) helps preserve lean muscle and improves satiety, so you're more likely to keep the muscle you have and stick to your diet. That's why this tool bumps the protein default when you select the Cutting goal.
What percentage of calories should come from fat?
There's no single right percentage, but roughly 20–30% of calories from fat is a sensible range for most people. Going below about 20% of calories or below ~0.5 g/kg of body weight can start to affect hormones (especially at low calorie targets), which is why this tool enforces a fat floor automatically.
Do I need to hit my macros exactly every day?
No. Aim for consistency across the week rather than perfection each day. Being within roughly ±5–10 g of your protein target and ±10–20 g on carbs and fat is more than enough for the vast majority of goals. Stress-free consistency beats obsessive precision.
Is this tool free with no signup?
Yes. The full protein / carb / fat breakdown, per-meal split, food equivalences and BMR calculator are all shown immediately, at no cost, with no account, email or credit card required. Everything runs in your browser.
Should I consult a dietitian instead?
This tool is designed for general fitness planning. If you have a medical condition — diabetes, kidney disease, a history of disordered eating, or you're pregnant or nursing — a registered dietitian can build a plan tailored to your labs, medications and history in a way no calculator can.
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