Metric example
A 30-year-old male at 180 cm and 75 kg has a Mifflin–St Jeor BMR of 1,730. At moderate activity: 1,730 × 1.55 = 2,681.5 estimated maintenance calories per day.
Estimate adult maintenance calories and explore fixed calorie adjustments for weight loss, maintenance, or weight gain using activity and BMR.
Daily calorie needs depend on resting energy use and activity. CalcRocket first estimates BMR, multiplies it by the selected activity factor to estimate maintenance calories, then applies the chosen fixed goal adjustment. Every result is an estimate, not an intake prescription.
Basal metabolic rate estimates energy used at rest. Total daily energy expenditure includes BMR plus movement, exercise, and digestion. This calculator approximates daily expenditure as BMR × activity multiplier; real-world expenditure can differ.
| Level | Typical activity | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise | 1.2 |
| Lightly active | Light exercise 1–3 days per week | 1.375 |
| Moderately active | Moderate exercise 3–5 days per week | 1.55 |
| Very active | Hard exercise 6–7 days per week | 1.725 |
| Extra active | Very hard exercise, physical job, or twice-daily training | 1.9 |
These fixed offsets show mathematical scenarios and are not recommendations.
0 kcal/day
-250 kcal/day
-500 kcal/day
+250 kcal/day
+500 kcal/day
The default BMR equation.
Male: 10W + 6.25H − 5A + 5 · Female: 10W + 6.25H − 5A − 161Available as an alternative and shown for comparison.
Male: 88.362 + 13.397W + 4.799H − 5.677A · Female: 447.593 + 9.247W + 3.098H − 4.330AA 30-year-old male at 180 cm and 75 kg has a Mifflin–St Jeor BMR of 1,730. At moderate activity: 1,730 × 1.55 = 2,681.5 estimated maintenance calories per day.
US height and weight are converted to centimeters and kilograms before the same BMR equation and selected activity multiplier are applied.
Results are estimates, not prescriptions. Actual needs vary with body composition, health, medications, pregnancy, breastfeeding, climate, training volume, and other factors.
This calculator is intended for adults and must not be used for children or teenagers. Very low calorie targets can be unsafe. Consult a qualified healthcare professional or registered dietitian for personalized advice.
Daily needs vary. This calculator estimates maintenance calories by multiplying equation-based BMR by a selected activity factor, then shows an optional goal adjustment.
BMR estimates resting energy use. Total daily energy expenditure includes BMR plus activity, exercise, and digestion. This calculator approximates TDEE with an activity multiplier.
Choose the description that most closely reflects a typical week. Activity categories are broad, so consider comparing adjacent levels when your schedule varies.
There is no universally appropriate deficit. CalcRocket displays fixed mathematical adjustments, not recommendations. A registered dietitian or qualified healthcare professional can assess an appropriate plan.
Safety depends on the individual and resulting intake. A 500-calorie adjustment can produce an unsuitable target, especially when maintenance needs are lower. Seek professional advice.
Equations cannot fully account for body composition, health, medications, pregnancy, breastfeeding, climate, training volume, and individual metabolism.
BMR is not a direct intake threshold, and calorie planning should consider overall health and activity. Consult a qualified professional before using a very low target.
No. It is intended for adults ages 18 to 120 and should not be used for children or teenagers.
Recalculate when weight, activity, health, training, or goals meaningfully change. Treat each result as a current estimate rather than a fixed prescription.
The underlying historical BMR equations use male and female constants derived from population data. They do not capture every person’s body composition or physiology.