Macro Calculator
Split your calories into protein, carbs and fat macros.
✓ Professional standard Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.
Macro Calculator is a free online medical & health tool from Toolinza. Split your calories into protein, carbs and fat macros. It runs entirely in your browser — your data is never uploaded — needs no signup, and works on any device. Toolinza offers 293+ free tools used by people across the UK, USA, Canada, Australia, the EU, India, Pakistan, the Middle East and worldwide.
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About the Macro Calculator
Calories decide whether you lose or gain weight, but macros — protein, carbs and fat — shape how you look, perform and feel while you do it. Getting enough protein in particular helps preserve muscle and keep you full.
This Macro Calculator splits your daily calories into protein, carbohydrate and fat targets based on your goal, turning a calorie number into a practical eating plan.
How to use the Macro Calculator
- Enter your daily calorie target (or work it out first).
- Choose your goal and preferred macro split.
- The tool divides calories into protein, carbs and fat.
- See your daily grams for each macro.
Key features of the Macro Calculator
- Splits calories into protein, carbs and fat
- Goal-based macro ratios
- Prioritises protein for muscle and fullness
- Turns calories into a practical plan
- Private — calculated in your browser
How the Macro Calculator works
This calculator applies standard, peer-reviewed formulas used by health professionals and public-health bodies worldwide. Depending on the metric, that includes the World Health Organization (WHO) classification, NHS and CDC guidance, the Mifflin-St Jeor equation for metabolic rate, and the U.S. Navy method for body composition. Inputs are converted between metric and imperial units using exact factors so results are consistent whichever system you use.
All calculations are performed in your browser, so the health information you enter is never sent anywhere.
Tips & best practices
- Prioritise protein — it preserves muscle in a deficit and keeps you fuller, which makes any plan easier to stick to.
- Work out your calorie target first with the Daily Calorie (TDEE) calculator, then split it into macros here.
- Macros are a framework, not a straitjacket; hitting your protein and calories consistently matters most.
Standards & accuracy
Uses internationally recognised clinical formulas — WHO, NHS, CDC, the U.S. Navy method and Mifflin-St Jeor — for screening-grade estimates.
Important: these tools provide screening-grade estimates for general information and education only. They are not a medical diagnosis and do not replace professional advice. Always consult a qualified healthcare provider before making health decisions.
Who uses the Macro Calculator?
- Planning meals to hit a calorie and protein target
- Supporting fat loss while keeping muscle
- Fuelling training and performance
- Following an IIFYM-style approach
Privacy & security
The Macro Calculator runs entirely inside your web browser. Your data — whether that is a file, figures or text — is processed on your own device and is never uploaded to a server, stored or shared. There is no signup and no account, so you can use it as often as you like while keeping full control of your information. This makes it a safe choice even for confidential and sensitive work.
Why choose Toolinza?
- 100% free — no hidden charges, watermarks or usage caps.
- Private & secure — your data stays on your device.
- Standards-compliant — accurate results suitable for the UK, USA, Canada, Australia, EU, India, Pakistan, the Middle East and worldwide.
- Works everywhere — desktop, tablet and mobile.
Frequently asked questions
Macros are the three macronutrients — protein, carbohydrate and fat — that make up your calories. Balancing them affects muscle retention, energy and how full you feel.
Protein needs vary, but a higher intake helps preserve muscle and control appetite, especially in a calorie deficit. The calculator sets a protein target based on your goal.
No. Treat them as a helpful framework. Consistently meeting your protein and calorie targets matters most; carbs and fat have more flexibility.
Yes. The Macro Calculator is completely free with no signup, no watermarks and no usage limits. Toolinza is supported by unobtrusive advertising so every tool stays free.
Absolutely. This tool runs entirely in your browser — your data and files are never uploaded to any server, so everything stays private on your own device.
No. The Macro Calculator works instantly in any modern web browser on desktop, tablet and mobile — Windows, macOS, Linux, Android and iOS.