Macro Split Calculator

Macro split calculator for calories to protein, carbs, and fat

A macro split is a simple way to turn a calorie target into an actionable plan: how many grams of protein, carbohydrates, and fat you aim to eat per day. This macro split calculator converts your daily calories into grams and shows how those grams translate into calorie contribution from each macro. If you want a quick starting point, the percentage method gives you a clean split (for example 30% protein, 40% carbs, 30% fat). If you want a more practical training-focused approach, the grams-per-kg method lets you set protein and fat targets based on your bodyweight and then automatically assigns the remaining calories to carbs.

Most people struggle with macros for one reason: they mix units. Calories are energy, macros are grams, and the conversion is not intuitive. Protein and carbs contribute about 4 calories per gram, while fat contributes about 9 calories per gram. This calculator handles that conversion for you and returns a balanced output that you can use in meal planning. It also includes a per-meal breakdown (3 meals and 4 meals) so you can see what “today’s macros” look like in the real world, not just as a daily total.

How to use it: start with a daily calorie target you can realistically hit. If you are unsure, use a target you have already been tracking, or pick a conservative number that matches your current bodyweight trend. Then choose a method. Percentages are good for fast planning and for people who do not want to think about bodyweight targets. Grams per kg is better for lifters and athletes because it anchors protein and fat to something meaningful, which helps consistency when calories change across dieting, maintenance, or bulking phases.

In percentage mode, enter three numbers that sum to 100%. The calculator converts each percentage into calories and then into grams. This is the clearest way to compare splits like 40/30/30 versus 25/50/25. In grams-per-kg mode, enter your bodyweight, then set your protein and fat targets in grams per kg. If you leave those blank, the calculator uses sensible defaults (protein 1.6 g/kg and fat 0.8 g/kg). Your carbs are then calculated as the remaining calories after protein and fat are accounted for, which is a realistic “fill the rest” approach used in many nutrition plans.

Interpreting the results: grams are your daily targets, not a requirement to hit perfectly every day. Many people track weekly averages because daily life varies. Protein is often prioritized for satiety, muscle repair, and lean mass support. Fat is important for hormones, essential fatty acids, and food enjoyment, but it is calorie-dense, so it needs control when cutting. Carbs are a flexible lever for training performance and energy. If your carb number comes out low, you might notice workouts feel harder, or you might need to raise calories or lower fat slightly depending on your goals and preferences.

Finally, remember that macro targets are tools. They do not replace food quality, sleep, or training. They also do not need to be perfect to work. The best split is the one you can follow consistently while moving in the right direction over weeks, not days. Use this calculator to create a baseline, test it for 10 to 14 days, and adjust based on real outcomes: bodyweight trend, gym performance, hunger, and recovery.

Assumptions and how to use this calculator

• Energy conversions use 4 kcal per gram for protein and carbs, and 9 kcal per gram for fat.
• Percentages must sum to 100% for the percentage method to produce a consistent split.
• Grams-per-kg method defaults to protein 1.6 g/kg and fat 0.8 g/kg if left blank.
• Carbs are calculated as remaining calories after protein and fat in grams-per-kg mode.
• This tool estimates targets and does not account for medical conditions, athlete-specific needs, or dietary restrictions.

Common questions

Which method should I use: percentages or grams per kg?

Use percentages if you want a simple split and you do not want to base targets on bodyweight. Use grams per kg if you train regularly and want protein and fat anchored to a bodyweight-based target, with carbs flexing up or down depending on calories.

What if my percentages do not add up to 100%?

This calculator requires your protein, carbs, and fat percentages to total 100%. If they do not, adjust them until they do. A good quick fix is to set protein and fat first, then make carbs the remaining percentage.

Why can carbs become very low in grams-per-kg mode?

If your protein and fat targets are high relative to your calorie target, there may be very few calories left for carbs. In that case, lower fat slightly, lower protein slightly, or raise calories. For most people, protein and fat targets should not consume nearly all daily calories.

Can I use this calculator for weight loss or muscle gain?

Yes. The calculator only translates calories into macros. Whether it supports weight loss or gain depends on the calorie target you choose and your consistency. Track results over 2 to 4 weeks and adjust calories first, then refine macros if needed.

How do I improve accuracy if I do not know my calorie needs?

Use your current intake as a starting point. Track your food for 7 days, take a daily scale weight, and look at the weekly average. If weight is stable, that intake is close to maintenance. Then adjust calories up or down and recalculate macros using this tool.