How to use this calculator
Enter adult measurements and select an activity factor to compare a formula-based maintenance estimate with fixed higher or lower calorie scenarios.
How the estimate is calculated
The tool estimates resting energy with Mifflin–St Jeor and multiplies it by the selected activity factor. The displayed scenarios subtract or add 250, 500 or 750 kcal/day from that maintenance estimate.
Its macro illustration uses 2.2 grams of protein per kilogram of body weight, 25% of maintenance calories from fat and the remaining calories from carbohydrate. These are calculator assumptions rather than measured needs.
What the estimate cannot tell you
The activity factor is approximate. A fixed calorie offset does not predict a constant rate of weight change, and the macro illustration may be unsuitable for a particular person. Do not interpret a displayed scenario as a safe prescribed intake; pregnancy, illness and other medical needs require individual assessment.
Worked example
If estimated resting energy is 1,600 kcal/day and the selected factor is 1.5, estimated maintenance is 2,400 kcal/day. A minus-250 scenario displays 2,150 kcal/day.