Your maintenance calories are the number of calories you need each day to keep your weight exactly where it is — neither losing nor gaining. For women, this number depends on age, height, current body weight, and typical activity level. This calculator estimates your maintenance needs using the Mifflin-St Jeor equation, one of the most widely validated formulas for predicting resting energy expenditure in healthy adult women.
Enter your measurements, choose your activity level, and press calculate. The tool returns your basal metabolic rate (BMR), your activity-adjusted maintenance calories, and a step-by-step breakdown of the math. Whether your goal is weight loss, lean muscle gain, or simply understanding your daily energy needs, this calculator provides a practical, evidence-based starting point.
🧮 Maintenance Calorie for Women
📊 Result
Formula Explained
The Mifflin-St Jeor equation, developed in 1990 and validated in numerous follow-up studies, estimates basal metabolic rate (BMR) for women as:
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161
BMR is the energy your body burns at complete rest to keep the heart beating, lungs breathing, brain functioning, and body temperature regulated — typically 60–70% of total daily energy expenditure. Maintenance calories are found by multiplying BMR by an activity factor that reflects average daily movement, including work, commuting, household tasks, and planned exercise. Learn more about the Mifflin-St Jeor equation on Wikipedia.
This calculator also supports the Katch-McArdle formula: BMR = 370 + 21.6 × lean body mass (kg). Because it uses lean mass instead of total weight, it can be more accurate for athletic women when body fat percentage is measured with a reliable method such as DEXA or hydrostatic weighing. When you select Katch-McArdle, an extra body fat input appears; enter your measured percentage there.
Activity Level Reference Table
Choosing the right activity factor is the single largest source of error in any calorie estimate. Use this standard reference, based on the values popularized by health authorities and adopted by most nutrition textbooks:
| Activity Level | Description | Factor |
|---|---|---|
| Sedentary | Little or no exercise, desk job | 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 | Hard daily exercise plus a physical job | 1.9 |
Women who are unsure between two levels should usually start with the lower one, because most people overestimate how much they move. A fitness tracker that records active minutes can help you decide more objectively.
Step-by-Step Guide
Worked example 1 — metric units: A 35-year-old woman, 70 kg, 170 cm, moderately active (factor 1.55).
BMR = 10 × 70 + 6.25 × 170 − 5 × 35 − 161 = 700 + 1062.5 − 175 − 161 = 1426.5 kcal/day
Maintenance = 1426.5 × 1.55 ≈ 2,211 kcal/day
Worked example 2 — US units: A 28-year-old woman, 145 lb, 5 ft 5 in (65 in), lightly active (factor 1.375).
Weight = 145 ÷ 2.20462 ≈ 65.8 kg; Height = 65 × 2.54 = 165.1 cm
BMR = 10 × 65.8 + 6.25 × 165.1 − 5 × 28 − 161 = 658 + 1031.9 − 140 − 161 = 1388.9 kcal/day
Maintenance = 1388.9 × 1.375 ≈ 1,910 kcal/day
The quick-fill profile buttons on the calculator show realistic combinations for different lifestyles. Start with the closest match, then fine-tune the fields with your own numbers, switching kg/lb and cm/in as needed.
Tips & Best Practices
- Weigh yourself first thing in the morning, after using the bathroom and before food or drink, for the most consistent reading.
- Re-calculate whenever your weight changes by about 5 lb (2–3 kg), because BMR is weight-dependent.
- Track intake for 1–2 weeks to see whether weight is stable. If it drifts, adjust by roughly 100–150 kcal per day until weight levels out.
- For weight loss, aim for a deficit of 300–500 kcal per day; for lean gain, add 200–300 kcal. Both are best paired with resistance training.
- Remember that estimates are starting points, not laws. Genetics, muscle mass, thyroid function, and sleep quality all shift individual metabolism.
Factors Affecting Accuracy
The Mifflin-St Jeor equation predicts BMR within about 10% of measured values for most healthy adult women, but several factors can move your true needs away from the estimate. Muscle is metabolically active tissue, so women with a higher proportion of lean mass burn more at rest — a key reason the Katch-McArdle option exists. Pregnancy, breastfeeding, and athletes in heavy training have elevated energy demands that standard formulas do not fully capture. Very low-calorie diets can lower metabolic rate as a protective response, while substantial weight gain increases it because more tissue must be supported. The activity multiplier is a rough band as well: someone who walks 15,000 steps a day plus trains three times a week may sit between "moderately active" and "very active." Treat the result as a hypothesis to test against real weight trends, refined over a couple of weeks of honest tracking.
Frequently Asked Questions
How is maintenance calories different from BMR? BMR is energy needed at complete rest. Maintenance calories add the calories burned through daily activity, exercise, and the digestion of food — often called non-exercise activity thermogenesis and the thermic effect of food.
Can I use this calculator for weight loss or gain? Yes. Subtract 300–500 kcal from maintenance for slow, sustainable fat loss, or add 200–300 kcal for lean muscle gain. Re-evaluate every few weeks as your weight changes.
Why does my fitness tracker show a different number? Wearables estimate energy expenditure from heart rate and movement data and can be wrong by 10–20% in either direction. Use them for trends, not absolute truth.
What if I eat exactly at this number and still gain weight? The estimate may be off, your activity factor may be too high, or your tracking may under-report portions. Drop the activity level one step or reduce intake by 100–150 kcal and observe for two weeks.