Macro Calculator
Work out your daily calories and how to split them into protein, carbs and fat. Choose a goal and a macro ratio to get gram targets based on your stats and activity level.
What macronutrients are
Your calories come from three macronutrients: protein, carbohydrate and fat. (Alcohol is a fourth source of energy but not a nutrient your body needs.) Macros are where the idea of "calories" becomes practical food choices, because each gram of each macro supplies a fixed amount of energy. Tracking macros, rather than only total calories, lets you steer not just how much you eat but the make-up of your diet — enough protein to hold onto muscle, enough carbs to fuel training, and enough fat for hormones and absorbing vitamins.
This calculator first estimates the daily calories appropriate for your goal, then divides them among the three macros according to the split you choose, converting each share into grams you can actually aim for at the dinner table.
How to use this calculator
Enter your age, sex, height, weight and activity level, then pick a goal (cutting, maintenance or bulking) and a macro split. The result is a daily calorie figure plus gram targets for protein, carbs and fat. Treat them as daily averages rather than rules to hit to the gram. If you are new to tracking, start by nailing your calorie total and protein, and let carbs and fat flex around your training and preferences.
How it's calculated
The conversion relies on fixed, well-established energy values: protein provides 4 calories per gram, carbohydrate 4 calories per gram, and fat 9 calories per gram. So once the calculator knows your daily calorie target and your chosen percentage split, the grams follow directly. For example, if 30% of a 2,000-calorie diet comes from protein, that is 600 calories ÷ 4 = 150 g of protein. The same logic gives carbs (÷ 4) and fat (÷ 9).
A sensible protein target for active people is roughly 1.6–2.2 g per kilogram of body weight; the calculator's higher-protein splits move you toward that range, which is especially helpful when cutting (protein preserves muscle and keeps you full) or bulking (protein supplies the building blocks for new muscle). Fat is usually kept to at least about 0.6–0.8 g/kg to support hormone health, with carbohydrate filling the remaining calories to fuel workouts.
Worked example
Suppose your goal-adjusted target is 2,200 calories on a balanced 30% protein / 40% carb / 30% fat split. Protein: 30% × 2,200 = 660 cal ÷ 4 ≈ 165 g. Carbs: 40% × 2,200 = 880 cal ÷ 4 = 220 g. Fat: 30% × 2,200 = 660 cal ÷ 9 ≈ 73 g. Those three gram targets together add back up to your calorie total.
| Goal | Protein | Carbs | Fat | Best for |
|---|---|---|---|---|
| Balanced | 30% | 40% | 30% | General health, easy adherence |
| Cutting (high-protein) | 40% | 30% | 30% | Fat loss while keeping muscle |
| Bulking | 30% | 50% | 20% | Building muscle, fuelling training |
| Lower-carb | 35% | 20% | 45% | Appetite control, preference |
| Endurance | 25% | 55% | 20% | High-volume cardio fuel |
Limitations & tips
There is no single "best" macro split — research consistently shows that adherence matters more than the precise ratio, provided protein is adequate and total calories fit your goal. Choose the split that matches your training and the foods you enjoy, because a plan you can follow for months beats a "perfect" one you quit in a week. Per-gram counting can also become stressful or obsessive for some people; if that is you, focusing on a protein target plus whole-food choices is a gentler approach. These are general estimates, not personalised nutrition advice — anyone with a medical condition, an eating-disorder history, or specific athletic goals should speak with a registered dietitian.
Frequently asked questions
How are macros calculated?
We estimate your daily calories (your TDEE adjusted for your goal), then split them by your chosen ratio. Protein and carbs are 4 calories per gram and fat is 9, so the gram targets follow from the calorie split.
What macro split should I choose?
Balanced (30/40/30) suits most people. Higher protein helps when losing fat or building muscle, while lower-carb or endurance splits suit specific training. Aim for 1.6–2.2 g of protein per kg of body weight.
Do I have to hit my macros exactly?
No — treat them as daily targets to aim for. Hitting your calorie total and protein target matters most; carbohydrate and fat can flex around your preferences and training without much downside.
Why is fat 9 calories per gram but protein and carbs only 4?
Fat is a more energy-dense molecule, so the same weight of fat packs more than twice the calories of protein or carbohydrate. That's why fatty foods add up quickly and why even healthy fats like oils and nuts should be measured if you're tracking closely.
Which macro is most important for losing fat?
Protein. It helps preserve muscle in a calorie deficit, keeps you fuller for longer, and has the highest thermic effect (your body burns more digesting it). That's why cutting-focused splits raise protein while trimming carbs or fat.
Is a low-carb or low-fat split better?
For most people, neither is clearly superior once protein and total calories are matched — studies comparing them find similar results. Pick the one that controls your appetite and fits your tastes and training, since the best split is the one you can sustain.
Sources & references
- National Academies (Institute of Medicine) — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids — establishes the Acceptable Macronutrient Distribution Ranges framework behind splitting calories across protein, carbs and fat.
- "Dietary Guidelines for Americans, 2020–2025" (PMC, National Institutes of Health) — federal guidance on healthy eating patterns and macronutrient balance.
Last updated: July 2026 · How we calculate
BriskToolbox provides estimates for general information only and is not medical advice. Talk to a healthcare professional about your individual health.