Calorie Calculator
Find your daily calorie targets for maintaining, losing, or gaining weight based on your body and activity level.
Example
A 30-year-old man weighing 80 kg at 180 cm with moderate activity (1.55):
BMR = 10(80) + 6.25(180) - 5(30) + 5
= 800 + 1125 - 150 + 5 = 1780 kcal
Maintain = 1780 x 1.55 = 2759 kcal/day
Mild loss = 2759 - 500 = 2259 kcal/day
Gain = 2759 + 500 = 3259 kcal/day
How it works
We compute your Basal Metabolic Rate with the Mifflin-St Jeor equation, multiply by your activity factor for maintenance calories, then subtract or add 500 for mild weight loss or gain.
Good to know
This Calorie Calculator estimates how many calories you burn in a typical day and turns that into three concrete targets: a maintenance number to hold your current weight, a mild-loss number (500 calories below maintenance), and a gain number (500 above). You enter your sex, age, height in centimetres, weight in kilograms, and pick an activity level from sedentary to extra active; everything is computed live in your browser. It's aimed at anyone planning a diet, a bulk, or a recomposition who wants a realistic starting calorie budget rather than a one-size-fits-all guess.
Reach for it at the start of a new eating plan, when your weight has stalled and you want to recheck your numbers, or any time you change activity level (for example, switching from a desk routine to training five days a week). Because the activity multiplier ranges from 1.2 to 1.9, the same body can show a maintenance figure that differs by several hundred calories depending on how honestly you rate your week, so choosing the right level matters more than fine-tuning your weight to the gram.
To read the result, treat the maintenance figure as your baseline daily energy and the mild-loss or gain figures as adjusted budgets, not promises. The smaller BMR stat is the energy your body would use at complete rest; the maintenance number is BMR multiplied by your activity factor. These are estimates from population averages, so use them as a 2 to 4 week experiment: track your actual weight trend and intake, then nudge the target up or down based on what really happens.
- Practical tip: most people over-estimate activity. If you sit for work and train a few times a week, "Light" or "Moderate" is usually more accurate than "Very active," and starting lower keeps your deficit or surplus from being unintentionally wrong.
Frequently asked questions
Why is the men's and women's formula different?
The Mifflin-St Jeor equation adds +5 for men and subtracts 161 for women to account for average differences in body composition, so women's BMR estimates come out about 166 kcal lower for the same height, weight, and age.
How much weight does a 500-calorie deficit lose?
A daily deficit of roughly 500 calories adds up to about 3,500 per week, the rough energy equivalent of one pound of fat, so the mild-loss target aims for about 0.5 kg (1 lb) per week.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser; nothing is uploaded.
Is this a substitute for medical advice?
No. These are educational estimates — consult a qualified health professional for medical decisions.
People also ask
What is a good daily calorie intake to lose weight?
A common starting point is a deficit of about 500 calories below your maintenance level, which targets roughly 0.5 kg (1 lb) of loss per week. Individual needs vary with body composition, activity, and health, so the right number is the one that produces a steady, sustainable trend for you.
How accurate is the Mifflin-St Jeor equation?
Mifflin-St Jeor is generally regarded as one of the more accurate predictive BMR equations for the general population, typically landing within about 10 percent of measured resting energy for many people. It is still an estimate based on averages and does not account for individual factors like muscle mass or medical conditions.
Does this calculator work with pounds and feet/inches?
This tool takes height in centimetres and weight in kilograms. To convert, multiply inches by 2.54 to get centimetres and divide pounds by 2.205 to get kilograms before entering your values.
Why did my calorie needs go down as I got older?
The Mifflin-St Jeor formula subtracts 5 calories per year of age, reflecting the average decline in metabolic rate as people get older. This is why an older person of the same height and weight will see a slightly lower estimate than a younger one.
What's the difference between BMR and maintenance calories?
BMR (basal metabolic rate) is the energy your body uses at complete rest just to stay alive. Maintenance calories are your BMR multiplied by an activity factor, representing total daily energy use including movement and exercise.
Is it safe to eat at the calorie deficit this tool suggests?
This calculator provides educational estimates only and does not give medical advice. A roughly 500-calorie deficit is a commonly cited moderate target, but appropriate intake depends on your individual health, so consult a qualified professional before making significant diet changes.
Why does my weight stay the same even at the maintenance number?
Maintenance is an estimate from population averages, so your true figure may be somewhat higher or lower. If your weight is steady, that figure is effectively your real maintenance; adjust your target up or down based on the trend you observe over a few weeks.
How often should I recalculate my calorie needs?
It's reasonable to recheck when your weight changes noticeably, when your activity level shifts, or every few weeks during an active diet or bulk. As your body and routine change, your maintenance number changes with them.
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