Starting keto? This free keto macro calculator sets your daily fat, protein and (capped) carbs from your stats, goal and carb limit — with the caveat that keto isn’t right for everyone.
Estimates for general guidance. Keto sets a low carb cap, moderate protein and the rest from fat. Maintenance is the starting point; goal targets use gentle, capped changes. A dietitian can tailor this safely.
How the Keto Macro Calculator Works
This calculator sets daily fat, protein and carb targets for a ketogenic-style eating pattern. It estimates your maintenance calories, adjusts for your goal, caps carbs at your chosen limit, sets protein by body weight, and fills the remaining calories with fat.
Formula: BMR = 10 × Weight (kg) + 6.25 × Height (cm) − 5 × Age + (5 for male, −161 for female). TDEE = BMR × Activity multiplier. Daily calorie target = TDEE (maintain), TDEE − 500 (lose), or TDEE + 300 (gain) — losing calories are never taken below a safe-minimum floor (1,500 kcal for men, 1,200 kcal for women). Carbs (g) = your selected daily carb limit (fixed). Protein (g) = 1.6 × Weight (kg). Fat (kcal) = Calorie target − (Carbs × 4) − (Protein × 4); Fat (g) = Fat (kcal) ÷ 9.
- Sex — male or female, used in the BMR formula and the safe-minimum calorie floor.
- Age, height and weight — in metric or imperial units, the core inputs to the BMR estimate; protein also scales directly from weight.
- Activity level — from sedentary to extra active, multiplies BMR to estimate maintenance calories.
- Goal — lose, maintain or gain, shifting the calorie target below or above maintenance.
- Daily carb limit — 20 g (strict), 30 g (moderate) or 50 g (relaxed); this is fixed regardless of your other inputs, and fat fills whatever calories remain after carbs and protein.
Example Scenarios
| Sex | Weight | Goal | Carb Limit | Calories/day | Fat | Protein | Carbs |
|---|---|---|---|---|---|---|---|
| Male, 30yr | 75 kg | Maintain | 20 g (strict) | 2,662 kcal | 234 g | 120 g | 20 g |
| Male, 35yr | 90 kg | Lose | 20 g (strict) | 2,033 kcal | 153 g | 144 g | 20 g |
| Female, 28yr | 60 kg | Maintain | 30 g (moderate) | 1,596 kcal | 121 g | 96 g | 30 g |
| Female, 55yr | 55 kg | Lose | 20 g (strict) | 1,200 kcal* | 85 g | 88 g | 20 g |
Height assumed at 178 cm (male rows) and 165/160 cm (female rows). *The last row hit the 1,200 kcal safe-minimum floor for women, so the calculator shows that floor instead of a lower deficit figure.
How to Adjust Your Keto Macro Calculator Targets Over Time
Treat the numbers from a keto macro calculator as a starting point, then adjust with real feedback. Protein is usually the anchor, carbs stay capped, and fat is the lever you move to reach your calorie goal.
- Recalculate after a noticeable weight change. A lighter body needs less energy, so the keto macro calculator will lower your fat target.
- Do not cut protein to chase ketosis unless a professional advises it, because eating too little protein can cost you muscle.
- Count carbs one way. Decide whether you track total or net carbs and stick with the method you chose in the keto macro calculator.
- Listen to hunger and energy. If you feel constantly hungry at the fat target the keto macro calculator suggests, the deficit may be too aggressive.
Keto is not suitable for everyone. Speak to a doctor first if you take diabetes or blood pressure medication, are pregnant or breastfeeding, or have kidney, liver or gallbladder problems. The ketogenic diet article on Wikipedia covers its history and known side effects, worth reading before relying on a keto macro calculator for months.
Keto Macro Calculator FAQ
Is a ketogenic diet safe for everyone?
No. Ketogenic diets aren't appropriate for everyone — they're generally not advised in pregnancy, for type 1 diabetes, or for certain kidney or pancreatic conditions, and can interact with some medications. Anyone with a medical condition should talk to a doctor or dietitian before starting.Why is protein based on my weight instead of my calorie target?
This calculator sets protein at a fixed 1.6 g per kg of body weight regardless of calorie goal, which is a commonly used moderate-protein level for ketogenic eating. Fat is then used as the flexible remainder to fill out your remaining calories.Why does carb intake stay the same even if I change my calorie goal?
The daily carb limit (20, 30 or 50 g) is a fixed choice you make directly, independent of your calorie target or goal. Only protein and fat adjust to fill the rest of your calories around that fixed carb amount.What's the difference between the strict, moderate and relaxed carb limits?
They represent different levels of carbohydrate restriction: 20 g is a stricter, more classic ketogenic limit, 30 g is a moderate approach, and 50 g is more relaxed, sometimes used for entry into a lower-carb pattern rather than strict ketosis.Why does my calorie target sometimes not drop as much as I expect?
Like other calorie tools on this site, the lose goal won't set a target below a safe-minimum floor of 1,500 kcal for men or 1,200 kcal for women, even if your calculated deficit would otherwise go lower.Can I use this calculator instead of the regular macro calculator?
Use this one specifically if you're following, or considering, a ketogenic-style low-carb diet with a fixed carb cap. For a standard balanced, higher-protein or lower-carb (but not keto-strict) split, the regular macro calculator gives more flexible percentage-based splits.Related Calculators
If you want to double-check your carb intake against food labels, the net carb calculator is a natural companion to this one. For a more flexible, non-keto macro split, see the macro calculator, and the TDEE calculator can help you sanity-check your maintenance calorie estimate on its own.