Protect Your Orderi
from Loss, Damage Or Stolen A$2.09
Macro Calculator
Three steps for your daily protein, carbohydrate and fat targets. Free, and you do not need to hand over an email to see them.
The short answer
Your macros are your daily targets for protein, carbohydrate and fat, in grams. Work out your calorie target first, set protein from your bodyweight and goal, set fat sensibly, and let carbohydrate take the remainder. This calculator does that in three steps and shows the whole method.
- Protein is set from your bodyweight, not from a fixed percentage of your calories.
- Carbohydrate moves the most between goals, because it absorbs whatever calories are left.
- The same answers always produce the same numbers.
- 1. About you
- 2. Activity
- 3. Goal
About you
These four details set your baseline. Metric units, since this is built for Australia.
years
cm
kg
If you know it from a DEXA or InBody scan, this makes the estimate more accurate. Leave it blank if you are guessing.
%Two quick checks
If either applies to you, generic calorie targets are the wrong tool and we will point you somewhere better instead.
What your macros actually are
Your macros are the three nutrients that carry energy: protein, carbohydrate and fat. Splitting your calories between them is what turns a calorie target into something you can shop for and cook.
The split is not arbitrary and it is not the same for every goal. Protein is set first, from your bodyweight and what you are trying to do. Fat is set next, high enough to be sensible rather than as low as possible. Carbohydrate takes whatever calories are left, which is why it moves the most between goals.
- Protein: 2.2 g per kg when losing fat, 2 g per kg when building muscle, 1.8 g per kg when maintaining.
- Fat: the higher of 0.8 g per kg or 22% of your calories, with a floor it will not go below.
- Carbohydrate: the remainder, with a floor of 50 g before the calculator starts trimming fat instead.
Why the split changes with your goal
Losing fat applies an 18% reduction against your estimated maintenance. Building muscle adds 10%, and gaining size adds 15%. Maintaining sits at your estimate, and recomposition sits just under it.
Protein stays high while calories come down, which is the main reason the percentage split looks so different between a fat loss target and a maintenance target even though the grams per kilo have barely moved.
How these numbers are produced
Every figure on the results page comes from a fixed calculation, not from an AI guess. The same answers always produce the same numbers, which is why you can come back next month, enter the same details, and get the same targets.
An AI model writes the explanation you read underneath the numbers. It is given the figures after they have been calculated and it is not allowed to change them, recalculate them, or quote a figure the calculation did not produce.
- Resting energy is estimated with the Mifflin-St Jeor equation, or the Katch-McArdle equation if you tell us your body fat percentage, which is the more accurate of the two when that figure is known.
- Your activity multiplier comes from your weekly training sessions and how physical your work day is. The scale runs from 1.2 for sedentary to 1.9 for very high activity.
- We deliberately lean conservative on activity. Overestimating maintenance is the most common failure in consumer calculators, and it quietly makes every goal harder.
How this compares with the Australian guidance
The Australian Nutrient Reference Values, published by the NHMRC and the New Zealand Ministry of Health, set the Recommended Dietary Intake for protein at 0.84 g per kg of bodyweight per day for men aged 19 to 70, which is 64 g per day, and 0.75 g per kg for women, which is 46 g per day.
This calculator targets more than that: between 1.8 and 2.2 g per kg depending on your goal. That is a deliberate difference, and it is worth understanding why rather than assuming one of the two figures is wrong.
An RDI is the amount that meets the needs of nearly everyone in the general population. It is a floor set to prevent deficiency, not a target chosen to support resistance training or to protect muscle while you are eating less than you burn. Those are different questions with different answers.
The same reference values set no upper limit for protein, stating that there are insufficient data to do so, while recommending a ceiling of 25% of energy from protein. This calculator caps protein at 35% of your calories, so on a lower calorie target it can sit above that recommended ceiling. If that matters to you, and it reasonably might, a dietitian is the right person to ask.
Source: Australian Nutrient Reference Values: Protein (NHMRC and NZ Ministry of Health)
Fibre and water
Fibre is set at 14 g per 1000 calories, so it scales with how much you are eating. The Australian Nutrient Reference Values set an Adequate Intake of 30 g per day for men and 25 g per day for women, so on most targets this calculator will land above the Australian figure rather than below it.
Water is estimated at 35 ml per kg of bodyweight, with an allowance added on training days. It is a starting point, not a rule. Heat, sweat rate and what you eat all move it.
The limits built into this calculator
A calorie target handed to a stranger needs guardrails, so several are built in and cannot be overridden.
- Fat loss is capped at 1% of your bodyweight per week. Faster than that is not a setting you can choose here.
- Your calorie target never drops below the higher of your estimated resting energy and an absolute floor of 1500 calories for men or 1200 for women.
- There are no goal weight projections and no "you will reach X by this date" timelines, because those numbers are not knowable and they set people up to feel they have failed.
- If your details fall outside what a general calculator should answer, it stops and points you to a doctor or an Accredited Practising Dietitian instead of producing a number anyway.
What this calculator is not
This is general information. It is not personalised dietary advice and it is not medical advice. It cannot see your blood work, your training history, your medication or your relationship with food.
If you are managing a health condition, if you are pregnant or breastfeeding, if you have a history of disordered eating, or if you simply want targets built around your actual situation, speak to a doctor or an Accredited Practising Dietitian. That is a better use of your time than any calculator.
Common questions
How do I calculate my macros?
Work out your calorie target first, then split it. Estimate your resting energy from your height, weight, age and sex, multiply it by an activity factor to get maintenance, then adjust for your goal. Set protein from your bodyweight, set fat, and give carbohydrate the remainder. That is exactly what this calculator does, and the method is set out in full below.
What should my macros be to lose weight?
Calories come down and protein stays up. This calculator applies a reduction against your estimated maintenance and holds protein at the higher end, because that is the macro with the clearest reason not to fall with your calories. Fat loss is capped at 1% of bodyweight per week and your target never goes below the higher of your resting energy and an absolute floor.
Is it better to count calories or macros?
Calories decide whether your weight moves. Macros decide what that weight is made of, and how the day feels to eat. If you are only going to track one thing, track calories. If you are training and want to hold on to muscle while losing fat, protein is the second thing worth tracking, and after that the split matters much less than people think.
What is the 40-40-20 rule for macros?
It refers to a fixed percentage split, most often given as 40% carbohydrate, 40% protein and 20% fat. This calculator does not use fixed percentages, because a share of calories is the wrong unit for protein. Protein needs track your bodyweight, so a fixed percentage gives a heavier person too little and a lighter person more than they need, and it drifts further out the deeper the deficit goes.
How do I calculate the macros in my food?
From the nutrition panel, per serve rather than per 100 g, and then multiplied by how much you actually ate. A tracking app does the arithmetic and holds a food database, which is where most people do this. This calculator sets the targets; it does not track what you eat against them.
What makes a macro calculator worth using?
Three things. It should show you its method rather than producing a number from nowhere. It should be conservative with the activity multiplier, since overestimating maintenance quietly stalls every goal. And it should have limits it will not cross, whatever you ask it for: a calculator that hands over any deficit you request is not being helpful.
Why is my protein target higher than the Australian RDI?
Because they answer different questions. The RDI of 0.84 g per kg for men and 0.75 g per kg for women is set to prevent deficiency across the whole population. This calculator targets a higher intake to support resistance training and to protect muscle while eating in a deficit. If that difference concerns you, a dietitian is the right person to ask.
Are the results the same every time?
Yes. The calculation is fixed, so identical answers always produce identical targets. Only the written explanation underneath varies, and it is not permitted to change any of the numbers.
