VHOSPITAL.CLINIC · Health Tools
Estimate how many calories you need each day to keep your current weight. This calculator is for adults aged 18 and over and gives a range, not an exact number.
Enter your age (18 or over), height and weight to see an estimate.
Resting energy (Mifflin-St Jeor): 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), then +5 for men or −161 for women.
Daily needs = resting energy × physical activity level (PAL). The FAO/WHO/UNU ranges are 1.40–1.69 for a sedentary or light lifestyle, 1.70–1.99 for an active or moderately active lifestyle, and 2.00–2.39 for a vigorous lifestyle.
How does this calorie calculator work?
It estimates your resting energy use with the Mifflin-St Jeor equation, which uses your sex, age, height and weight, and multiplies it by the physical activity level range for your lifestyle from the FAO/WHO/UNU report on human energy requirements.
How accurate is the estimate?
It is an estimate. Studies comparing the Mifflin-St Jeor equation with measured energy use find it is among the better equations, but for an individual it can be more than 10% out, and it is less accurate in older adults and people with severe obesity.
Who should not use this calculator?
It is for adults aged 18 and over. It is not suitable during pregnancy or breastfeeding, for children, or for people with medical conditions that affect weight or nutrition. If you want to lose or gain weight, a GP, practice nurse or registered dietitian can help you set a safe target.
General information only, not medical or dietary advice. Last updated 2026-11-13.