Choose the equation honestly
Mifflin–St Jeor uses age, sex, height and weight. Katch–McArdle uses estimated lean mass, so an inaccurate body-fat input directly changes the result.
Energy and nutrition planning model
Compare calorie methods before choosing a target.
Estimate resting energy with three published equations, apply an explicit activity factor, translate a weight-change scenario into a calorie adjustment, and turn the daily total into macros, meals and a static projection.
Adult planning estimate only. Not for pregnancy, breastfeeding, people under 18 or treatment of a medical condition. The activity multiplier is an assumption, not a measured energy expenditure.
Method and limitations
Calorie planning needs feedback, not blind precision
Published resting-energy equations estimate an average response. Your actual maintenance intake is better refined from several weeks of consistent intake and weight observations.
Treat activity as a hypothesis
Activity multipliers compress work, exercise and daily movement into one number. Compare the predicted maintenance level with real trends and revise gradually.
Expect adaptation
The straight-line chart uses roughly 7,700 kcal per kilogram as planning arithmetic. Metabolism, water, adherence and changing body size mean real progress will not be linear.
Macro math
Protein and carbohydrate are allocated at 4 kcal per gram; fat at 9 kcal per gram. The remainder after protein and fat is assigned to carbohydrate.
Weekly variation
The optional high/low-day schedule preserves the same weekly average. It is a scheduling illustration, not evidence that calorie cycling changes energy balance.
When to get help
Large planned changes, low intake, medication effects, medical conditions or a history of disordered eating warrant guidance from a qualified clinician or dietitian.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.