How this calculation works
The calorie scenario starts with an activity-adjusted resting estimate and adds or subtracts a daily energy amount for the weekly weight change you enter. Its fixed 7,700 kcal per kilogram conversion is simplified arithmetic, not a forecast that your body will change at that rate. Real weight change is dynamic; metabolism, body composition and water weight change over time.
Worked example
This example uses illustrative inputs. Your current result is shown above.
Using the male equation at 70 kg, 175 cm, age 30 and moderate activity gives estimated maintenance of 2,556 kcal/day. Entering −0.25 kg/week produces −0.25 × 7,700 ÷ 7 = −275 kcal/day. The arithmetic scenario is 2,556 − 275 = 2,281 kcal/day; it does not promise a weekly loss of 0.25 kg.
Assumptions and limits
- The 7,700 kcal/kg conversion is held constant and does not model metabolic adaptation, changing body mass, fluid changes or the composition of weight gained or lost.
- TDEE itself is an uncertain estimate using broad activity factors. This is not a personalised diet, a safe-intake assessment or an eating plan.
- A low-number warning does not establish that every higher number is safe. Do not use this model for children, pregnancy, lactation, illness or an eating-disorder context; seek qualified advice.
Questions people ask
Will following this number produce exactly the entered weight change?
No. The tool converts a planned change into a static energy scenario. Individual responses and energy expenditure change over time.
Why does a negative weekly change lower the result?
The sign controls the arithmetic: a negative change subtracts from estimated maintenance, while a positive change adds to it.
Does the cited NIDDK model validate the fixed 7,700 rule?
No. NIDDK’s dynamic modelling explains why simple fixed conversions cannot accurately predict long-term weight change. This calculator does not implement that dynamic model.