Macro Calculator
Macronutrient targets depend on who you are and what you’re training for. Feed the calculator your age, sex, weight, height, activity level and goal (cut, maintain, or gain) and it computes total daily calories using the Mifflin-St Jeor equation plus an activity multiplier, then splits those calories into grams of protein, carbohydrate and fat using the macro profile you pick (balanced, high-protein, keto, low-fat, or fully custom).
How the macro split is built
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1
Enter body stats
Sex, age, weight and height feed the BMR formula.
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2
Pick activity level
From sedentary (1.2) to very active (1.9). Multiplier on BMR gives TDEE.
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3
Set goal
Cut subtracts 10–25% from TDEE, gain adds 10–20%, maintain uses TDEE as-is.
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4
Choose macro profile
Balanced, high-protein, keto, low-fat or custom percentages.
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5
Read grams per day
The tool shows calories, grams of each macro and per-meal breakdown.
The BMR formulas
Mifflin-St Jeor (the current standard for most adults):
- Male: BMR = 10·kg + 6.25·cm − 5·age + 5
- Female: BMR = 10·kg + 6.25·cm − 5·age − 161
Activity multipliers (TDEE = BMR × factor)
| Level | Factor | Example |
|---|---|---|
| Sedentary | 1.2 | Desk job, little exercise |
| Lightly active | 1.375 | Light walk 1–3 days/week |
| Moderately active | 1.55 | Training 3–5 days/week |
| Very active | 1.725 | Hard training 6–7 days/week |
| Extremely active | 1.9 | Manual job + training, or two-a-days |
Macro profiles
| Profile | Protein | Carbs | Fat | Typical use |
|---|---|---|---|---|
| Balanced | 30% | 40% | 30% | General fitness |
| High-protein | 40% | 30% | 30% | Strength, body recomp |
| Keto | 25% | 5% | 70% | Ketogenic diet |
| Low-fat | 30% | 55% | 15% | Endurance training |
| Custom | any | any | any | Coached plans, cutting |
Gram math
- Protein: 4 kcal/g. A 30% protein target on a 2,400-kcal plan = 720 kcal / 4 = 180 g.
- Carbs: 4 kcal/g. 40% on 2,400 kcal = 240 g.
- Fat: 9 kcal/g. 30% on 2,400 kcal = 80 g.
Sanity-check your targets
- Protein floor for active adults: 1.6–2.2 g per kg of body weight is the current evidence-backed range for muscle retention and growth.
- Fat floor: don’t go below ~0.6 g/kg for extended periods; hormone production suffers.
- Rate of loss: 0.5–1% of body weight per week is sustainable for most people. Faster losses come with muscle loss and rebounds.
- Recalculate every 4–6 weeks. Your TDEE drops as you lose weight; static targets stop working.
Frequently Asked Questions
It’s the most accurate common BMR equation in large validation studies, within ~10% for most adults. It under-estimates for very muscular people (use Katch-McArdle if you know your body fat %) and over-estimates for obese individuals.
Two common reasons: you over-estimated your activity level (most people actually sit at 1.2–1.375, not 1.55), or you’re targeting an aggressive deficit. Dial activity down a notch and cut 10% rather than 25% to sanity-check.
No. Protein is the one macro worth hitting precisely; carbs and fat can swap some calories without much effect unless you’re training for a specific adaptation. Stay within ±10 g of your protein target and you’re fine.
Macros are a calorie framework, not a full nutrition plan. Aim for 25–35 g of fiber/day and get micros from a varied whole-foods base.
No. Weight, age, goal and all other inputs stay in your browser for this session only and are not transmitted.