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Estimate maintenance calories, choose a daily gap, and get a practical starting target with the formula and limitations shown clearly.
Your result
Estimate onlyWe’ll estimate resting needs, maintenance calories, and a starting target. The result is rounded to avoid false precision.
Maintenance and target shown separately
Low and inappropriate targets are blocked
Formula and assumptions explained below
For adults 18+ who are not pregnant or breastfeeding. This is an estimate, not medical advice or a meal plan. The calculator blocks underweight-screening results and uses conservative self-guided floors of 1,200 calories for the female equation and 1,500 for the male equation; individualized needs can still be higher.
Methodology
The result combines a published resting-energy equation with a simplified activity estimate. Each step adds uncertainty, so the final number is deliberately rounded.
Mifflin–St Jeor estimates resting energy expenditure from age, height, weight, and a female or male equation constant. The original study included 498 healthy adults aged 19–78.
The resting estimate is multiplied by the activity level you choose. Daily movement varies substantially, so maintenance is better understood as a starting estimate than a measured burn.
The calculator subtracts 250, 500, or 750 calories, checks whether the result is appropriate for a self-guided estimate, and rounds to the nearest 50 calories to avoid false precision.
Read the number well
Maintenance calories are the estimated intake that would keep weight roughly stable at the selected activity level. The target is that estimate minus your chosen daily gap.
Real weight change is not perfectly linear. Metabolism, activity, food measurement, water balance, sleep, health conditions, and medication can all move the result. The CDC describes gradual loss of roughly one to two pounds per week as more likely to be maintained, but that population guidance is not an individual guarantee.
If you use the estimate, compare it with several weeks of real-world trend rather than reacting to one day. If you feel unwell, have a clinician-directed nutrition plan, or are unsure whether a deficit is appropriate, use qualified individual guidance instead.
Keep exploring
A calorie-deficit estimate answers “where could I start?” If you are planning around a goal date or checking a measurement, use the more specific tool.
A smaller gap is usually the better place to start. This calculator offers 250, 500, and 750 calories per day, then checks the result against your estimated maintenance needs. A higher option is not automatically better, and the calculator blocks combinations that produce an inappropriately low self-guided target.
No. The familiar 3,500-calorie rule is a rough shortcut, not a promise. Energy expenditure changes over time, and sleep, activity, medication, health conditions, food measurement, and normal water shifts can all affect what you observe.
It is a starting estimate. Mifflin–St Jeor predicts resting energy expenditure from age, height, weight, and a sex-specific constant. An activity multiplier introduces more uncertainty, so the result is rounded to the nearest 50 calories rather than presented as an exact prescription.
It is intended for adults 18 and older who are not pregnant or breastfeeding. It is not appropriate for children, for anyone whose measurements fall below the adult BMI screening range, or when a clinician has prescribed a nutrition target. People with an eating-disorder history, significant medical conditions, or medicines that affect weight or appetite should use individualized professional guidance.
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