Macro Calculator
Split a daily calorie target that you enter into protein, carbohydrate and fat. Use balanced, higher-protein or lower-carb presets or your own percentages totalling 100%, and see calories and grams per day for each macro.
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About the Macro Calculator
Macro Calculator turns a daily calorie target that you enter into grams of protein, carbohydrate and fat. Choose a balanced (30/40/30), higher-protein (40/30/30) or lower-carb (30/20/50) split, or enter your own percentages — they must add up to exactly 100%. The tool shows the calories and grams for each macronutrient using the standard energy values of 4 kcal per gram for protein and carbohydrate and 9 kcal per gram for fat.
It does not estimate how many calories you need and does not recommend a diet; the calorie target, split and any fibre figure are your own choices. You can optionally record a fibre target you are tracking, which is shown as entered. Macro targets are personal estimates: if you have a health condition, are pregnant or breastfeeding, have or have had an eating disorder, or have special dietary needs, please seek advice from a qualified professional.
How to use
- Enter your daily calorie target.
- Pick a preset or type your own protein, carbohydrate and fat percentages.
- Make sure the percentages add up to exactly 100%.
- Optionally enter a fibre target you track.
- Click Calculate, then copy or download the summary.
Key features
- Calorie target entered by you — no TDEE estimate.
- Balanced, higher-protein, lower-carb and custom splits.
- Exact 100% check for custom percentages.
- Calories and grams per day for each macro.
- Optional user-entered fibre target.
- Calculation breakdown, copy and download summary, Reset.
Best practices
- Use a calorie target agreed with a professional if you have health needs.
- Treat the grams as a flexible guide rather than a strict rule.
- Check food labels, as energy values per gram are averages.
- Change one thing at a time and review how you feel.
- Seek qualified advice for pregnancy, medical conditions or a history of disordered eating.
Benefits
- Clear grams-per-day numbers from your own target.
- Easy comparison of different splits.
- Transparent calculations.
- Private: nothing is stored.
Frequently asked questions
How are grams calculated?
Each macro’s calories are the target multiplied by its percentage. Protein and carbohydrate calories are divided by 4, and fat calories by 9, to give grams per day.
Does this tool tell me how many calories to eat?
No. You enter the calorie target yourself. This tool only splits it into macronutrients and does not recommend an intake.
Why must the percentages add up to 100%?
The three percentages divide the whole calorie target. If they add up to more or less than 100%, the grams would not match your target, so the tool asks you to correct them.
Is the fibre target a recommendation?
No. It is optional, entered by you and shown as entered. Fibre is part of total carbohydrate, so it is not added on top.
Which preset should I choose?
There is no single right split. Presets are simple starting points; preferences, activity and health needs differ, and a registered dietitian can help you choose.
Is this suitable during pregnancy or with a medical condition?
Please seek advice from a qualified health professional. Macro targets are personal estimates and may not suit pregnancy, medical conditions, eating disorders or special diets.
Is my information saved?
No. Everything is calculated in your browser. Your measurements, dates and results are not sent anywhere or saved in browser storage, and Reset clears them from the page.