Macro Calculator — Daily Protein, Carbs & Fat Targets
Calculate your daily macros free — protein, carbs and fat — based on your body, activity and goal. Uses the Mifflin-St Jeor formula, with diet-style presets and food equivalents. No sign-up, completely private.
Last updated: June 2026
Your daily targets
- Calories
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- Protein
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- Carbohydrates
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- Fat
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To hit your protein target
Medical Disclaimer: This tool provides general nutrition estimates for educational purposes only and is not medical or dietary advice. Calorie and macro needs vary by individual. Consult a qualified healthcare professional or dietitian before making significant changes to your diet.
About this tool
Hit your goals by counting macros, not just calories
Calories tell you how much energy you eat; macros tell you what that energy is made of. The three macronutrients — protein, carbohydrates and fat — each play a different role, and getting the balance right is what separates simply eating less from actually changing your body composition. A macro calculator turns your goal into concrete daily gram targets you can track.
This tool starts with the Mifflin-St Jeor equation, the most accurate widely-used formula for basal metabolic rate, then applies an activity multiplier to estimate your total daily energy expenditure. It adjusts the calories for your goal — a 500-calorie deficit for fat loss, maintenance, or a 400-calorie surplus for muscle gain — and splits the result into protein, carbs and fat based on the diet style you pick, shown as a clear donut chart.
Protein gets prioritised in the high-protein and low-carb presets because it preserves muscle and keeps you full, which matters most when you're in a deficit. The per-meal breakdown and food equivalents — chicken breasts, eggs, scoops of whey — make the protein target feel achievable rather than abstract. Treat the numbers as a starting point, track your progress for a few weeks, and adjust. Everything runs privately in your browser, free and without an account.
How it works
Three quick steps — no account, nothing uploaded to a server.
Enter your details
Add your age, gender, weight, height and activity level.
Pick a goal & diet
Choose lose, maintain or gain, and a diet style.
Read your macros
See your calories and protein, carb and fat targets instantly.
General health information related to this tool is available from the US Dietary Guidelines (dietaryguidelines.gov). Last checked July 2026.
FAQ
Frequently asked questions
What are macros?
Macros — short for macronutrients — are the three nutrients your body needs in large amounts: protein, carbohydrates and fat. Protein and carbs provide about 4 calories per gram and fat about 9. 'Counting macros' means hitting daily gram targets for each rather than just tracking total calories, which gives you more control over body composition, energy and muscle retention while losing or gaining weight.
How are my macros calculated?
First the tool estimates your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation from your age, gender, weight and height. It multiplies that by an activity factor to get your total daily energy expenditure (TDEE), then adjusts the calories for your goal — a deficit to lose, maintenance, or a surplus to gain. Finally it splits those calories into protein, carbs and fat according to the diet style you choose.
How much protein should I eat?
Protein needs depend on your goal and activity, but common guidance is roughly 1.6–2.2 g per kg of body weight when building or preserving muscle, especially in a calorie deficit. The high-protein preset in this tool leans towards the upper end. Protein is the most satiating macro and protects muscle while dieting, which is why most fitness plans prioritise hitting it.
What's the best macro split for weight loss?
For fat loss, a higher-protein split (such as 40% protein, 35% carbs, 25% fat) works well for most people because protein preserves muscle and keeps you full in a calorie deficit. That said, the 'best' split is the one you can stick to — some prefer lower carbs, others need more for training. Use the diet selector to compare splits and pick one that fits your preferences and routine.
Is this macro calculator accurate?
It gives a solid, science-based starting estimate using the widely validated Mifflin-St Jeor formula, but everyone's metabolism, activity and body composition differ, so treat the numbers as a baseline. Track your weight and energy for two to three weeks and adjust calories up or down based on real results. It's an educational tool, not medical or dietary advice — consult a professional for personalised guidance.
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