Calorie Calculator
Estimate daily calorie needs.
lb to kg converter
How your daily calories are calculated
The calculator uses the Mifflin-St Jeor equation to estimate your resting energy, then scales it by how active you are. The example below uses a sample adult.
Men
10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women
10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Daily calories = BMR × activity factor
BMR = 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1,649 kcal
Maintenance = 1,649 × 1.375 = 2,267 kcal
To lose or gain about 0.5 kg (1 lb) a week, subtract or add roughly 500 kcal a day.
Activity levels and what they mean
| Activity level | Exercise | Multiplier | Your daily calories |
|---|---|---|---|
| Sedentary | Little or no exercise | × 1.2 | — |
| Light | 1-3 days a week | × 1.375 | — |
| Moderate | 3-5 days a week | × 1.55 | — |
| Active | 6-7 days a week | × 1.725 | — |
| Very active | Hard daily exercise | × 1.9 | — |
Your calorie goals
Enter your details above to see your calorie goals chart.
Free calorie calculator: daily calories to lose, maintain or gain weight
About this tool
Tell us your age, height, weight and how active you are, and this calculator estimates how many calories your body burns in a day. You get your maintenance calories, plus a target to lose or gain about half a kilo a week. It is a quick, realistic starting point for planning meals, not a strict prescription.
Features
- Trusted formula: the Mifflin-St Jeor equation, a standard in nutrition practice.
- Metric or imperial: use kg and cm, or lb, feet and inches.
- Health alert that warns you when a weight-loss target drops below the commonly advised minimum.
- Goals chart and an activity table that show your calories at every activity level.
- PDF report and one-tap sharing, with an optional name on the report.
- Private and mobile friendly. Your details are never stored.
Good to know
If you are unsure which activity level to pick, choose the lower one. Results are estimates, so watch how your weight changes over two to three weeks and adjust by 100 to 200 calories if needed.
Frequently asked questions
What is BMR?
Basal metabolic rate (BMR) is the energy your body uses at complete rest for breathing, circulation and keeping cells working. It makes up most of the calories you burn in a day.
How are daily calories calculated?
First your BMR is estimated from your weight, height, age and sex with the Mifflin-St Jeor equation. It is then multiplied by an activity factor from 1.2 for a sedentary day up to 1.9 for hard daily exercise.
How many calories should I cut to lose weight?
A common rule of thumb is about 500 calories below maintenance a day, which is roughly 0.5 kg (1 lb) a week. Real progress varies because your body adapts over time, so treat it as a starting point.
What is the lowest safe daily calorie intake?
Many health organisations advise not going below about 1,200 calories a day for women or 1,500 for men without medical supervision. The health alert in this tool flags a weight-loss target under that level.
Why use the Mifflin-St Jeor equation?
It was developed in 1990 from measured data on 498 healthy adults, and later reviews found it among the most reliable equations for estimating resting energy in both lean and overweight adults.
Which activity level should I choose?
Pick the one that matches a typical week. A desk job with one or two workouts is usually Sedentary or Light. If you are between two levels, start with the lower one and adjust after a few weeks.
Is the result accurate for athletes or very muscular people?
It is an estimate. The equation does not know your body composition, so people with a lot of muscle often burn more than predicted, and others burn less. Individual needs can differ by a few hundred calories.
Do calorie needs change with age?
Yes. In this equation, every extra year lowers BMR by about 5 calories, reflecting the gradual loss of muscle with age. The tool is designed for adults and is not meant for children, teens or pregnancy.
Should I see a doctor before changing my diet?
If you have a medical condition, take medication, are pregnant or breastfeeding, or plan a large calorie cut, speak with a doctor or registered dietitian first.
Sources and further reading
The equation and guidance used here come from published research. The references below let you read the original sources yourself.
Peer-reviewed research
- A new predictive equation for resting energy expenditure in healthy individuals(opens in a new tab)
Mifflin et al., American Journal of Clinical Nutrition, 1990. The original Mifflin-St Jeor study.
- Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults(opens in a new tab)
Frankenfield et al., Journal of the American Dietetic Association, 2005. Systematic review.
- Quantification of the effect of energy imbalance on bodyweight(opens in a new tab)
Hall et al., The Lancet, 2011. How body weight responds to changes in calorie intake.
Health guidance
- Understanding calories(opens in a new tab)
NHS. Plain-language guide to calories and daily energy needs.
- Dietary Guidelines for Americans(opens in a new tab)
U.S. Department of Agriculture and Department of Health and Human Services.
Medical disclaimer
This calculator is for general information and education only. It is not a medical device and does not give a diagnosis, treatment or personal medical advice. Calorie estimates can be off for athletes, older adults, people with medical conditions and anyone who is pregnant or breastfeeding. Always talk to a doctor or registered dietitian before making big changes to your diet, and never ignore professional advice because of a result you saw here.