What are macros?

"Macros" is short for macronutrients — the three nutrients that supply all of your calories: protein, carbohydrates, and fat. Protein and carbohydrates each provide 4 calories per gram, while fat provides 9 calories per gram. Counting macros (rather than just calories) helps you eat in a way that supports your goal, whether that is losing fat, building muscle, or maintaining your current weight.

How this macro calculator works

Enter your daily calorie target and pick a goal. The calculator splits those calories into a protein, carb, and fat ratio suited to that goal, then converts each percentage into grams using the 4/4/9 calories-per-gram values. If you do not yet know your calorie target, work it out with our TDEE calculator and subtract around 500 calories to lose weight or add 500 to gain.

Which macro split should I choose?

A balanced 30/40/30 split works well for general health and maintenance. For fat loss, a higher-protein split (around 40/30/30) helps preserve muscle and keeps you fuller. For muscle gain, more carbohydrates (around 30/45/25) fuel hard training. Low-carb eaters often prefer a 40/20/40 split. There is no single "best" ratio — consistency and hitting your protein target matter most.

Using this as a Leangains macro calculator

The Leangains approach (popularised by Martin Berkhan) combines 16:8 intermittent fasting with a high-protein diet and carb cycling: more carbohydrates on training days, more fat and fewer carbs on rest days. To calculate Leangains macros here, first set your calories about 10 to 20 percent above maintenance on training days and 10 to 20 percent below on rest days, then run the calculator twice: pick the high-protein 40/30/30 split for rest days and the muscle-building 30/45/25 split for training days. Keep protein high and roughly constant on both days; it is the anchor of the Leangains method.

Frequently asked questions

How much protein do I need?

A common guideline is 1.6–2.2 g of protein per kg of body weight (about 0.7–1 g per pound), especially if you exercise. The high-protein presets above are built around this range.

Do I have to hit my macros exactly?

No. Treat them as targets to aim for. Getting within 5–10 g of each is plenty for steady progress.

What macros should I use for Leangains?

Keep protein high every day (around 2 g per kg of body weight or more), eat most of your carbohydrates on training days, and shift towards fat on rest days. The 40/30/30 and 30/45/25 presets above map well to rest and training days respectively.

Disclaimer: This calculator provides estimates for informational purposes only and does not constitute medical or dietary advice. Consult a qualified professional before making significant changes to your diet.