Calorie Calculator
Estimate daily calorie needs from age, weight, height, sex used for the equation, and activity level. The calculator shows a Mifflin-St Jeor basal metabolic rate, an activity-adjusted maintenance estimate, and a modest example deficit. It is a starting point for planning, not a diagnosis or a prescription. Bodies vary, activity estimates are noisy, and medical conditions, pregnancy, medications, and eating disorders require qualified guidance. Your values remain in this browser tab.
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Add to Chrome — freeWhat it does
- Mifflin-St Jeor BMR estimate
- Five activity multipliers
- Maintenance and gentle-deficit figures
- Metric inputs with local calculation
How to use Calorie Calculator
- 1
Enter body measurements
Provide age, weight in kilograms, and height in centimeters so the equation has explicit units.
- 2
Choose the equation inputs
Select the sex value used by the published Mifflin-St Jeor constants and choose the closest activity level.
- 3
Read the estimates
Compare BMR with maintenance and treat the deficit line as an example rather than a mandatory target.
How it works
Interpreting a calorie estimate
Basal metabolic rate is a formula estimate for resting energy, not a direct measurement of metabolism. Maintenance adds an activity multiplier that compresses many routines into one broad category. Bodies can still differ because of composition, training, illness, sleep, medication, and age-related changes. Use the result as a starting scenario, observe real trends, and adjust cautiously. Do not use an online estimate to set extreme restriction or override clinical advice; a rounded range is more honest than a precise-looking target.
The Mifflin-St Jeor calculation estimates resting energy from weight, height, and age, then applies a sex-specific constant. The activity selection multiplies that result by a conventional factor from sedentary through extra active. A small illustrative deficit is subtracted from maintenance; it is not a claim about the correct deficit for every person. Calculations are metric and remain local.
Use the result carefully
The most useful way to use this page is as a hypothesis. Choose the activity level that matches an ordinary week, record intake and weight trends over several weeks, and adjust with a clinician or dietitian when necessary. Day-to-day scale changes include water, food volume, and hormonal effects, so one reading cannot validate or disprove the equation. Keep the estimate rounded and avoid treating it as a permission to ignore hunger, recovery, or medical advice.
Units and interpretation
Scenario checklist
Record the inputs beside any estimate, especially the activity assumption and whether the calculation is being used for maintenance or a gradual change. Recalculate when weight, height, routine, or health circumstances change. A trend across several weeks is more informative than a single scale reading, and a professional should guide decisions that involve illness, pregnancy, medication, or disordered eating.
The page expects kilograms and centimeters, not pounds and inches. Convert inputs before entering them rather than mixing unit systems inside the formula. Activity multipliers are broad descriptions: a desk job with occasional walks is different from structured training several days each week. If your routine changes, recalculate the scenario; the calculator does not track exercise sessions or automatically update itself.
Record whether the displayed target is being used for maintenance, gradual change, or simply comparison. A small calculation error is less important than a false sense of precision, so round sensibly and evaluate sustained energy, sleep, recovery, and health signals rather than chasing a single daily number.
Examples
Moderately active adult
The activity multiplier changes the maintenance estimate, while BMR is the resting equation result.
Comparing activity assumptions
This demonstrates why choosing an honest activity level matters more than reporting a falsely precise number.
Frequently asked questions
Is this calorie calculator a medical recommendation?
No. It is an estimate from a population equation and an activity multiplier, not medical advice or a personalized meal prescription. Illness, pregnancy, age, medications, body composition, training load, and eating history can change what is appropriate. Discuss meaningful diet changes with a qualified clinician.
Which formula does the calorie calculator use?
It uses the Mifflin-St Jeor equation with metric inputs, then multiplies the estimated BMR by one of five activity factors. The result is rounded for display, so it should be treated as a practical starting estimate rather than an exact measurement of metabolism or a guarantee of weight change.
Should I eat the gentle-deficit number every day?
Not automatically. The deficit figure is a simple example derived from the maintenance estimate, and it does not screen for nutritional needs or unsafe restriction. Track real trends over time, avoid extreme targets, and get professional support when weight, health, or eating behavior is a concern.