Free tool
Macro Calculator
Your TDEE, daily calorie target, and protein / carb / fat split in grams — calculated with the same formulas registered dietitians actually use. No email required.
Calculator
Your numbers
Used for BMR only — biological sex drives the formula constant.
Enables the Katch-McArdle formula (more accurate if you know it).
Target daily calories
2,763 kcal
144 g
576 kcal · 21%
374 g
1,496 kcal · 54%
77 g
691 kcal · 25%
Under the hood
How this calculator works
There are three steps, in order: estimate the energy your body spends just being alive (BMR), scale that for how much you move (TDEE), then nudge it up or down for your goal and split the remaining calories across the three macros.
1. BMR — basal metabolic rate
Default formula is Mifflin-St Jeor, validated in 1990 and still the most accurate population-wide predictor for adults:
- Male:
BMR = 10·kg + 6.25·cm − 5·age + 5 - Female:
BMR = 10·kg + 6.25·cm − 5·age − 161
If you enter a body fat percentage we switch to Katch-McArdle, which is more accurate for lean or very muscular users because it works off lean body mass:
BMR = 370 + 21.6·leanMassKg
2. TDEE — total daily energy expenditure
BMR multiplied by an activity factor:
- Sedentary — 1.2
- Light (1–3 days/wk) — 1.375
- Moderate (3–5 days/wk) — 1.55
- Heavy (6–7 days/wk) — 1.725
- Athlete (2-a-days or physical job) — 1.9
3. Goal adjustment + macros
Target calories are TDEE × a goal multiplier (−25% aggressive cut through +20% aggressive bulk). Protein is set per pound of bodyweight — scaling up for cuts (~1.1 g/lb) and down for bulks (~0.7 g/lb) — and fat takes the greater of a 0.35 g/lb floor or 25% of calories. Carbs fill whatever's left.
Calories are clamped to a safe floor ( 1,500 kcal for men, 1,200 kcal for women) so aggressive cuts can't return unsafely low numbers, and the tool warns you if protein plus fat already exhaust your calorie target.
How to pick an honest activity level
This is where most people overshoot. The activity multiplier already includes non-exercise movement — fidgeting, walking to the kitchen, errands — so if you work a desk job and lift 3x a week, you're Moderate, not Heavy. Heavy is for manual labor or serious daily training volume. Athlete is reserved for twice-daily training or a genuinely physical job (construction, moving, landscaping).
If you're unsure, start one tier lower than you think. It's easier to add calories when progress is too slow than to claw back from an unintentional surplus.
Use your numbers
Got your targets? These reads will help you hit them:
- Best protein powders → for hitting daily protein
- How to track macros (beginner guide) → logging + apps walkthrough
- High-protein meal prep guide → macros on autopilot
Frequently asked
Questions people ask about this
What's the difference between BMR and TDEE?
BMR (basal metabolic rate) is the energy your body uses at complete rest to keep you alive — breathing, circulation, cell maintenance. TDEE (total daily energy expenditure) is BMR multiplied by an activity factor, so it reflects what you actually burn on a typical day including exercise and non-exercise movement. You eat against TDEE, not BMR.
Which formula does this calculator use?
Mifflin-St Jeor by default — it's the most accurate population-wide formula for adults and the one most recommended by registered dietitians. If you enter a body fat percentage, we switch to Katch-McArdle, which calculates BMR from lean body mass and tends to be more accurate for lean or very muscular users.
How many calories should I eat to lose fat?
A 15–25% deficit below your TDEE is the sweet spot for most people. A moderate cut (−15%) preserves more muscle and is easier to sustain; an aggressive cut (−25%) loses weight faster but is harder to hold and raises the risk of muscle loss if protein and training aren't dialed in. Don't drop below roughly 1,200 kcal (women) or 1,500 kcal (men) long term without medical supervision.
How much protein do I actually need?
For active adults trying to build or keep muscle: roughly 0.7–1.0 g per pound of bodyweight (1.6–2.2 g/kg). Higher end when you're in a cut, lower end on a bulk. If you're very overweight, scale protein to lean body mass instead of total weight so you don't overshoot.
Do I need to hit my macros on rest days?
Yes, as a baseline — recovery, muscle repair, and hormonal function all continue on off days. Some people cycle carbs slightly (more on training days, less on rest days) while keeping protein and fat steady, but for most people consistent daily targets produce the best adherence and results.
Should I recalculate as I lose weight?
Yes. TDEE drops as bodyweight drops, so a target calculated at 200 lb will be too high when you hit 180 lb. Recalculate every 10–15 lb of change, or whenever progress stalls for 2–3 weeks despite consistent adherence.
Is this accurate for women, teenagers, or people over 60?
Mifflin-St Jeor was validated across a wide adult population and works reasonably well for women and older adults, but individual variance is real — two people with identical stats can differ by 200–300 kcal. Use this as a starting estimate, then track for 2–3 weeks and adjust based on actual scale and measurement trends. If you're under 18, pregnant, or have a medical condition, talk to a registered dietitian rather than relying on a calculator.
Why do my results seem much lower than other calculators?
Some calculators default to higher activity multipliers or less conservative goal adjustments. This tool uses the standard Mifflin-St Jeor multipliers (1.2–1.9) and caps cuts at 25% below TDEE with a hard calorie floor. If another calculator tells you a 5'6" sedentary woman on an aggressive cut should eat 900 kcal, that calculator is wrong — not this one.
This calculator is provided for educational purposes. It's a starting estimate, not medical advice — individuals vary, and targets should be adjusted based on real-world progress. If you're under 18, pregnant, have an eating disorder history, or a diagnosed metabolic condition, work with a registered dietitian or physician rather than relying on any calculator.