Macro Calculator (Food)

Macros — short for macronutrients — are the three main nutrients your body uses for energy: protein, carbohydrates, and fat. Protein supports muscle repair and growth (4 kcal/g), carbs are your body's primary fuel source (4 kcal/g), and fats support hormones and cell health (9 kcal/g). Tracking macros helps you hit specific body-composition goals beyond just counting calories.

It first calculates your Basal Metabolic Rate (BMR) using the Mifflin–St Jeor equation — the most validated formula for most adults. Your BMR is then multiplied by an activity factor to get your Total Daily Energy Expenditure (TDEE). Finally, a calorie adjustment is applied based on your goal: a 500 kcal deficit for weight loss, no change for maintenance, or a 300 kcal surplus for muscle gain.

The Balanced split (30/40/30) works well for general health and most recreational athletes. High Protein (40/35/25) is popular for muscle building or preserving lean mass during a cut. Low Carb (35/20/45) suits people who prefer fewer carbs or have moderate carb sensitivity. Keto (25/5/70) is a strict very-low-carb approach that shifts the body to fat-burning mode and requires careful adherence.

The results are evidence-based estimates derived from population-level DRI (Dietary Reference Intake) research and the Mifflin–St Jeor equation. Individual metabolism can vary by 10–15%, so treat the numbers as a strong starting point. Adjust your intake up or down based on real-world progress over 2–3 weeks, or consult a registered dietitian for a personalised plan.

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep you alive — breathing, circulating blood, and maintaining cell function. TDEE (Total Daily Energy Expenditure) adds the calories burned through physical activity on top of BMR. Your calorie and macro targets are based on TDEE, not BMR.

General guidelines suggest 0.8 g per kg of body weight for sedentary adults, rising to 1.6–2.2 g/kg for those doing regular strength training. This calculator distributes your protein target based on the macro split you choose and your total calorie goal, which typically lands within these evidence-backed ranges for active individuals.

Yes — select 'Weight Loss' as your goal and the calculator applies a 500 kcal daily deficit, which is widely recommended as a safe rate that supports roughly 0.5 kg (1 lb) of fat loss per week without sacrificing too much muscle. Pair the macro targets with adequate protein intake to preserve lean body mass during a deficit.

No — this calculator is designed for healthy non-pregnant adults. Nutritional needs during pregnancy, breastfeeding, or with conditions like diabetes or kidney disease differ significantly. If any of these apply to you, please consult a healthcare professional or use a dedicated tool such as the USDA DRI Calculator for Healthcare Professionals.