Macro Calculator

Macros (macronutrients) are the three main energy sources in food: protein, carbohydrates, and fat. Protein and carbs provide 4 kcal/g; fat provides 9 kcal/g. Hitting the right ratio — not just total calories — determines whether you lose fat while preserving muscle, build lean mass, or fuel performance. Two people eating the same calories but different macro splits will see very different results in body composition and energy levels.

For most active adults, 1.6–2.2 grams of protein per kilogram of body weight per day is optimal for muscle protein synthesis. The "Protein/kg" insight above shows exactly where your target lands. Sedentary adults need less (around 0.8 g/kg), but intakes up to 2.2 g/kg are safe and beneficial for anyone doing resistance training. Spreading protein across 3–4 meals rather than eating it all in one sitting maximizes absorption throughout the day.

For fat loss, higher protein works best: roughly 35% protein, 40% carbs, 25% fat. Elevated protein preserves muscle during a calorie deficit, increases satiety, and has a higher thermic effect — meaning you burn more energy digesting it. Lower-carb approaches like keto can also work, but research consistently shows total protein intake matters more than the exact carb/fat ratio for most people, so hitting protein first is the priority.

For muscle gain, aim for 35% protein, 45% carbs, 20% fat. Higher carbohydrates fuel training sessions and replenish muscle glycogen for recovery, while protein stays elevated to support muscle protein synthesis. Pair this split with a calorie surplus of 200–400 kcal above your TDEE and progressive overload training — this combination is the most evidence-backed approach for gaining lean mass without excessive fat gain.

IIFYM (If It Fits Your Macros) is a flexible dieting approach where you hit daily protein, carb, and fat gram targets without restricting specific foods. Rather than labeling foods "clean" or "dirty", you simply track and fit any food into your daily targets. Research consistently shows flexible dietary approaches produce better long-term adherence than rigid meal plans. The "Custom" goal in this calculator is designed for IIFYM practitioners who want to set their own ratios.

Select your number of meals per day and the calculator divides your daily targets evenly across each meal. In practice, you don't need perfectly equal meals — daily totals are what matter most. However, distributing protein relatively evenly across 3–4 meals rather than eating it all in one sitting does maximize muscle protein synthesis throughout the day. For carbs, front-loading around workouts is a useful performance strategy.

Calories measure total energy intake; macros describe where those calories come from. Protein and carbs each contain 4 kcal/g; fat contains 9 kcal/g. You can hit your calorie goal while eating very different ratios of protein, carbs, and fat — which produces different outcomes for body composition, energy, and performance. That's why athletes and body recomposition goals often track macros rather than calories alone: the source of your calories matters as much as the total.

Yes — AI-powered apps like Lemon Health go beyond just showing you macro targets. Lemon analyzes your meals, identifies where you're consistently under or over on specific macros, and suggests practical swaps and additions to help you hit your targets. It learns your food preferences and schedule over time, making macro tracking feel natural rather than obsessive — so you stay consistent long enough to see real results.