How to Calculate Your Calories and Macros

Most people who train seriously log their lifts. Far fewer log their food — and even fewer do it correctly. Eating at random and hoping body composition improves is the equivalent of walking into the gym without a program. It can work until it doesn't.

Tracking calories and macros is not about obsession. It's about having signal. Once you know your numbers, you can adjust them deliberately. That's what separates lifters who progress year after year from those who stall.

Why Tracking Matters

Your body weight changes based on one thing: the difference between energy in and energy out. Protein synthesis, strength gains, and fat loss are downstream of that equation. You can optimize training all day, but if your nutrition is chaotic, your results will be chaotic.

Tracking doesn't need to be permanent. Even four to six weeks of accurate logging teaches you the rough macronutrient profile of your diet. Many lifters track precisely during a cut or bulk, then maintain by feel once they've calibrated their instincts.

Step 1 — Calculate Your BMR

BMR (Basal Metabolic Rate) is the energy your body burns at rest — organs functioning, temperature regulated, nothing else. It's the floor of your caloric needs.

Mifflin-St Jeor Formula (most accurate for most people)

Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5

Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161

Step 2 — Calculate Your TDEE

TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. This accounts for the calories burned through daily movement and exercise.

• Sedentary (desk job, no exercise) → BMR × 1.2
• Lightly active (1–3 days/week training) → BMR × 1.375
• Moderately active (3–5 days/week training) → BMR × 1.55
• Very active (6–7 days/week hard training) → BMR × 1.725
• Extremely active (twice-a-day training, physical job) → BMR × 1.9

Continuing the example: TDEE = 1780 × 1.55 ≈ 2759 kcal/day. This is the maintenance number — eating at this level should hold your weight roughly constant.

Step 3 — Set Your Calorie Target

Once you have your TDEE, you apply an adjustment based on your goal. The adjustments below are conservative starting points — aggressive deficits or surpluses tend to work against you.

Fat Loss — Deficit of 300–500 kcal

A 500 kcal daily deficit creates roughly a 0.5 kg per week loss rate, which is the upper end of sustainable fat loss while preserving muscle. If you're strength training seriously, consider a 300–400 kcal deficit to minimise strength loss.

Muscle Gain — Surplus of 250–500 kcal

Natural muscle gain is slow. Beginners might gain 1–1.5 kg of actual muscle per month; intermediate lifters far less. A modest surplus of 250–300 kcal is usually sufficient for most. Larger surpluses mostly add fat.

Maintenance

Eat at TDEE. Useful during skill acquisition phases, during deloads, or when managing a high non-training stress load.

Step 4 — Split Your Macros

Macronutrients are protein, carbohydrates, and fat. Each has a caloric density:

• Protein — 4 kcal per gram
• Carbohydrates — 4 kcal per gram
• Fat — 9 kcal per gram

Protein — Set This First

Protein is non-negotiable for strength athletes. The current research consensus sits at 1.6–2.2 g per kg of bodyweight per day, with the upper range recommended for people in a caloric deficit or with high training volume.

Fat — Set a Minimum

Fat supports hormonal function, joint health, and fat-soluble vitamin absorption. Do not drop below 0.8–1.0 g per kg of bodyweight. Most lifters do well at 25–35% of total calories from fat.

Carbohydrates — Fill the Remainder

Carbohydrates are the primary fuel for high-intensity effort. They are not the enemy — they are the reason you can hit rep 5 as hard as rep 1. Remaining calories after protein and fat go to carbs.

Goal-Based Adjustments at a Glance

• Weight loss: TDEE − 400–500 kcal · protein at 2.2 g/kg · fat at minimum · carbs fill rest
• Muscle gain: TDEE + 250–300 kcal · protein at 1.8–2.0 g/kg · fat at 0.9–1.0 g/kg · carbs fill rest
• Maintenance: TDEE · protein at 1.6–2.0 g/kg · fat at 25–30% total · carbs fill rest

Practical Tips

• Weigh yourself at the same time each day (morning, post-bathroom, pre-food) and take a 7-day average. Single readings are noise.
• If weight is not moving as expected after 2–3 weeks, adjust calories by 100–150 kcal. Do not panic-cut or panic-add.
• Protein is the hardest macro to hit. Build meals around a protein source, then add carbs and fat around it.
• Tracking apps introduce error through database inconsistency and portion estimation. A 10% margin of error is normal — aim for consistency, not perfection.
• Refeeds (a single day at maintenance or slight surplus) during a long cut can help psychologically without meaningfully interrupting fat loss.
• Sleep affects hunger hormones directly. Poor sleep raises ghrelin (hunger) and lowers leptin (satiety). No macro split fixes a chronic sleep deficit.

These numbers are starting points. Your actual TDEE depends on factors that no formula fully captures — non-exercise activity thermogenesis (NEAT), gut microbiome, metabolic adaptation, and more. Treat the calculation as your baseline and let the scale tell you if it's right.