Calorie Calculator
Find your daily calorie target for maintenance, loss, or gain.
Convert a measurement
Calorie Calculator — your inputs
- Sex
- Male
- Age
- 30 yrs
- Height
- 175 cm
- Weight
- 70 kg
- Activity level
- Sedentary — little or no exercise
- Goal
- Maintain weight
- BMR formula
- Mifflin-St Jeor (default)
- Unit system
- Metric
Key takeaways
- Your calorie target is BMR × an activity factor, then adjusted for your goal. The BMR half is well validated; the activity half is the estimate.1
- A 500 kcal daily deficit is the conventional target for about half a kilogram (one pound) of loss a week. Faster is rarely better and costs more muscle.
- Predictive equations land within 10% of measured expenditure for roughly 70% of people.2 Treat the number as a starting point and let the scale correct it over three to four weeks.
- Do not eat below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision — below that, meeting micronutrient needs becomes genuinely difficult.5
- People under-report what they eat by 20 to 40% without meaning to.6 If the number is not working, this is the first thing to check, not the formula.
How to use this calculator
Enter your sex, age, height, and weight.
Pick your activity level and goal.
Optionally switch the BMR formula (Katch-McArdle needs a body fat %).
Understanding your result
Your calorie target combines your BMR (energy at rest), your activity level, and your goal. A daily deficit of ~500 kcal yields roughly 1 lb of loss per week.
We show all five goal options at once so you can compare without re-submitting.
Where the number comes from
Every calorie target is built in two steps, and they are not equally trustworthy. First, your basal metabolic rate — what you would burn lying still all day — is estimated from height, weight, age and sex. Then that figure is multiplied by an activity factor to reach total daily energy expenditure, and finally adjusted up or down for your goal.
The first step is good science. The Mifflin-St Jeor equation was derived in 1990 from indirect calorimetry on 498 healthy adults,1 and a systematic review of the competing equations found it the most reliable for non-obese and obese adults alike, predicting resting rate within 10% for about 70% of people.2 The second step is a judgement call dressed up as a multiplier. That is where nearly all the error lives.
| Level | Multiplier | What it means in practice |
|---|---|---|
| Sedentary | 1.2 | Desk job, little deliberate exercise, mostly seated day |
| Lightly active | 1.375 | Light exercise 1–3 days a week, or a job on your feet |
| Moderately active | 1.55 | Moderate exercise 3–5 days a week |
| Very active | 1.725 | Hard exercise 6–7 days a week |
| Extra active | 1.9 | Physical job plus hard daily training, or two-a-day sessions |
Most people overestimate their activity level
If you train hard four times a week but spend the other twenty-three hours of each day sitting, you are closer to lightly active than very active. When in doubt, pick the lower band — a target that turns out to be slightly low is corrected by eating a little more, which is a much easier problem than the reverse.
Choosing a deficit
A pound of body fat stores roughly 3,500 kcal, which is where the familiar 500-a-day-for-a-pound-a-week rule comes from. It is a decent approximation over weeks, and it becomes less accurate over months as your body gets smaller and cheaper to run. The National Academies' reference intakes describe energy requirements as a distribution rather than a single figure for exactly this reason: there is no one correct calorie number for a given person, only a range that shifts as they change.3
- 250 kcal — conservative0.3 kg/week
Slow, easy to sustain, minimal muscle loss
- 500 kcal — standard0.5 kg/week
The usual recommendation for most people
- 750 kcal — aggressive0.8 kg/week
Workable short-term; harder to adhere to
- 1,000 kcal — steep1 kg/week
Significant lean-mass loss; rarely advisable unsupervised
| Method | Value (kg/week) |
|---|---|
| 250 kcal — conservative | 0.3 |
| 500 kcal — standard | 0.5 |
| 750 kcal — aggressive | 0.8 |
| 1,000 kcal — steep | 1 |
Steeper is not better. The larger the deficit, the greater the share of the loss that comes from muscle rather than fat, and the harder the plan is to stick to — and adherence, not deficit size, is what predicts whether anyone is still on track in six months.
The floor is not a suggestion
Below roughly 1,200 kcal for women and 1,500 for men, hitting protein, calcium, iron and B-vitamin requirements becomes very difficult regardless of how carefully you eat.5 Very-low-calorie diets exist, but they are medically supervised for a reason.
Why the number stops working
Almost everyone who diets for long enough hits a point where the same intake stops producing the same loss. Three things are usually happening at once, and only one of them is the metabolism people blame.
- You are smaller. A lighter body costs less to maintain and to move. The target that created a 500 kcal deficit at the start creates a smaller one now, purely by arithmetic. Recalculate every 4–5 kg.
- You move less without noticing. Non-exercise activity — fidgeting, walking, standing — falls measurably in a deficit. It is not laziness and it is largely involuntary.
- Adaptive thermogenesis. Resting rate drops somewhat below what the size change alone predicts. This is real, and after extreme weight loss it can be large and lasting — the Biggest Loser follow-up found participants burning several hundred calories a day less than predicted six years later.4 For ordinary, moderate weight loss the effect is far smaller than that study is usually taken to imply.
- Intake has crept up. Portions drift, and under-reporting is the rule rather than the exception: doubly-labelled-water studies routinely find people eating 20–40% more than they record.6 Weighing food for a week is unglamorous and settles the question faster than anything else.
Using the number properly
- Treat it as a hypothesis. Eat at the target for two to three weeks and track weight. If the trend is not moving as expected, adjust by 10% rather than starting over.
- Weigh yourself the same way each time and read the weekly average, not the daily number. Day-to-day swings are water and gut contents, and can easily exceed a week of real fat loss.
- Set protein first. It protects muscle in a deficit and is the most satiating macronutrient — the Protein Calculator gives a target by bodyweight and goal.
- Split the rest with the [Macro Calculator](/calculators/macro-calculator). Carbohydrate and fat ratios matter far less than total calories and protein, so pick a split you can actually eat.
- Recalculate after meaningful weight change. This is the step almost everyone skips, and it is the most common reason a plan quietly stops working.
If you are pregnant or breastfeeding
Do not use a deficit. Energy needs rise in the second and third trimesters and during lactation. The Pregnancy Weight Gain Calculator applies the guidance that actually fits that situation.
Terms used on this page
- BMR (basal metabolic rate)
- Energy burned at complete rest, keeping your heart beating, lungs working and cells repairing. Usually 60–70% of total daily expenditure — the majority of your burn happens while you do nothing.
- TDEE (total daily energy expenditure)
- BMR plus everything you do: exercise, incidental movement, and the energy cost of digesting food. This is the number your intake is compared against.
- NEAT
- Non-exercise activity thermogenesis — fidgeting, walking, standing, gesturing. It varies by hundreds of calories a day between people and falls during a deficit without anyone deciding to move less.
- Adaptive thermogenesis
- The drop in energy expenditure beyond what the change in body size predicts. Real, measurable, and routinely exaggerated in popular coverage of dieting.
The formula
- Man, 30y, 175 cm, 70 kg, sedentary
- BMR = 10×70 + 6.25×175 − 5×30 + 5 = 1649
- TDEE = 1649 × 1.2 = 1979
Source: Mifflin-St Jeor + activity multipliers. Published clinical/scientific formula.
Limitations
- Formulas estimate average needs — your real expenditure varies day to day.
- Very low targets (below 1,200 women / 1,500 men kcal/day) need medical supervision.
- Activity multipliers are rough; track your weight trend and adjust.
References
- 1.A new predictive equation for resting energy expenditure in healthy individuals. Mifflin, St Jeor et al., American Journal of Clinical Nutrition 51(2):241–247, 1990.
- 2.Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults. Frankenfield et al., Journal of the American Dietetic Association 105(5):775–789, 2005.
- 3.Dietary Reference Intakes for Energy. National Academies of Sciences, Engineering, and Medicine, 2023.
- 4.Persistent metabolic adaptation 6 years after 'The Biggest Loser' competition. Fothergill et al., Obesity 24(8):1612–1619, 2016.
- 5.Dietary Guidelines for Americans, 2020–2025. U.S. Departments of Agriculture and Health and Human Services, 2020.
- 6.Misreporting of energy intake in the elderly using doubly labeled water to measure total energy expenditure. Sawaya et al., American Journal of Clinical Nutrition 63(4):491–499, 1996.
Frequently asked questions
Related calculators
BMR Calculator
Calculate your Basal Metabolic Rate — the energy your body burns at complete rest.
Open calculatorTDEE Calculator
Find your Total Daily Energy Expenditure and compare cut, maintain, and bulk targets.
Open calculatorMacro Calculator
Split your daily calories into protein, carbs, and fat — across five plans, or build your own.
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Read articleNot medical advice. This calculator is for general informational purposes only and is not a substitute for professional medical guidance. Always consult a qualified healthcare provider before making decisions about your health. Read the full medical disclaimer.
Printed from mystatura.com — for general information only, not medical advice.