BMR Calculator for Women
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at rest. It naturally declines with age and hormonal changes, especially during perimenopause and menopause.
How BMR works
Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions: breathing, circulating blood, cell production, and temperature regulation. It accounts for 60\u201375% of your total daily calorie burn.
This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate BMR formula for most adults. Your TDEE (Total Daily Energy Expenditure) multiplies your BMR by an activity factor to estimate total calories burned per day.
For women over 40, BMR is affected by hormonal changes that go beyond simple aging. Declining estrogen leads to loss of lean muscle mass, increased visceral fat, and changes in insulin sensitivity, all of which lower your metabolic rate. Understanding your BMR is the first step toward a nutrition plan that accounts for these shifts.
Why does metabolism slow during menopause?
Estrogen plays a key role in maintaining lean muscle mass, regulating fat distribution, and supporting insulin sensitivity. As estrogen declines during perimenopause and menopause, women tend to lose muscle and gain visceral fat, which lowers BMR. Additionally, declining NAD+ levels reduce mitochondrial efficiency, further impairing cellular energy production.
How can I boost my metabolism after 40?
Resistance training to maintain muscle mass, adequate protein intake (0.7\u20131g per pound of body weight), quality sleep, and stress management are foundational. Medical interventions like hormone replacement therapy (HRT), NAD+ supplementation, and GLP-1 medications can also meaningfully support metabolic health during and after the menopause transition.
What is TDEE and how is it different from BMR?
BMR is the energy your body uses at complete rest. TDEE (Total Daily Energy Expenditure) adds your physical activity on top of that. TDEE is the number that matters for weight management: eat below your TDEE to lose weight, at your TDEE to maintain, or above to gain.