Macro Calculator

Macronutrients — protein, fat, and carbohydrates — supply all the calories your body uses for everything from breathing to running marathons. Protein and carbs both deliver 4 calories per gram; fat delivers 9 calories per gram. Setting macro targets means deciding how to split your daily calorie budget between these three.

This calculator anchors protein first because it has the most evidence behind it: 0.7–1.0 g per pound of body weight (≈ 1.6–2.2 g/kg) preserves muscle in a deficit and builds it in a surplus. Then it sets fat as a percentage of total calories — typically 20–35%, with 25% as a balanced default. Carbohydrates fill whatever calories remain, fueling intense training and recovery.

The formulas: Calories = TDEE × (1 + adjust), where adjust is −20% for cut, 0 for maintain, +12% for bulk. Protein g = body weight (lb) × protein per lb. Fat g = (calories × fat%) ÷ 9. Carbs g = (calories − protein g × 4 − fat g × 9) ÷ 4. The protein and fat numbers stay consistent; carbs flex with your calorie target.

A 170 lb lifter has a TDEE of 2,400 cal/day and wants to lose fat at a moderate pace. Set goal to Cut: calories = 2,400 × 0.80 = 1,920/day. Protein at 0.9 g/lb = 153 g (612 cal). Fat at 25% of 1,920 = 53 g (480 cal). Carbs = (1,920 − 612 − 480) ÷ 4 = 207 g.

That's a typical fat-loss plan: high enough protein to protect muscle while in a deficit, moderate fat for hormones and satiety, and 200+ g of carbs to keep training quality high. Expect about 0.7–1.0 lb/week of weight loss — adjust calories by ±100 every 2–3 weeks based on the actual scale trend.

Same person on a Bulk: calories = 2,400 × 1.12 = 2,688/day. Protein stays at 153 g; fat rises to 75 g; carbs jump to 322 g. The added 768 cal/day fuel about 0.5 lb/week of gain — slow enough that most of it is muscle, not fat (assuming consistent training).

Protein: 0.7 g/lb is the floor for muscle retention; 0.9–1.0 g/lb is the well-supported sweet spot for lifters in a deficit. Going above 1.2 g/lb shows diminishing returns in nearly every published study. Spread across 3–5 meals of 30–50 g each.

Fat: don't drop below 20% of calories — fat is essential for hormone production (especially testosterone) and absorbing fat-soluble vitamins. 25–30% is a comfortable default. Endurance athletes often go lower (20%) to fit more carbs; strength athletes and folks who feel better on lower carbs can go 35%+.

Carbs: the flex variable. Fuel high-intensity training (lifting, sprinting, sports). If you train hard 4+ days/week, prioritize carbs. If you're sedentary, carbs are still fine but you'll likely feel best with a moderate share. Cyclical carb cycling is rarely worth the complexity for non-physique athletes.

Fiber: aim for 14 g per 1,000 cal (so ~25–35 g/day). Not a macro per se, but the single biggest predictor of diet adherence and satiety. Prioritize whole-food carbs (oats, beans, fruit, vegetables) over refined ones.

Underestimating portion sizes — handful estimates undercount nuts, oils, and nut butters by 30–50%. Use a food scale for the first 2–3 weeks until your eye is calibrated.

Forgetting cooking oils, dressings, and condiments — easy to add 200–400 hidden calories per day from olive oil, mayo, and butter.

Not adjusting calories as weight changes — TDEE drops about 25 cal/day for every 5 lb you lose. A plan that worked 4 weeks ago may need a 100-cal trim.

Treating cut/bulk numbers as eternal — re-pull TDEE every 4–6 weeks, especially after bodyweight or activity changes 5%+.

Skipping protein on training days — splitting protein across meals beats loading one giant dinner. Aim for 30–50 g protein at each main meal.

Ignoring weekly averages — daily variation of ±200 cal is normal. What matters is the 7-day average and the multi-week scale trend, not any single day.