- Enter current weight.
- Enter daily calorie balance. Use a negative number for a deficit and positive for a surplus.
- Set the projection period.
- Review estimated future weight and rate.
- Recalculate regularly. Update inputs as real progress changes.
Daily Weight Estimator
Project a future body weight from current weight, daily calorie balance, and number of days. The tool uses the common planning approximation that a cumulative 7,700-kilocalorie energy imbalance corresponds to about one kilogram of body-weight change.
Real weight change is not perfectly linear because metabolism, water, glycogen, appetite, and adherence change over time. Use the result as a rough scenario estimate rather than a guaranteed outcome.
Daily inputs
kg
kcal/day
days
Result
—
Calculated result
Estimated change—
Total calorie balance—
Weekly rate—
Weight change (kg) = daily calorie balance × days ÷ 7,700
Future weight = current weight + weight change
Future weight = current weight + weight change
What the result means
The result is a linear planning estimate of body weight after the chosen period.
Short-term scale changes may mainly reflect water and glycogen rather than tissue change.
Given: 80 kg, a 400 kcal/day deficit, 30 days.
Calculation: Change = −400×30÷7,700 = −1.56 kg. Future weight = 80−1.56 = 78.44 kg.
Result: About 78.4 kg.
Why can actual weight differ?
Energy expenditure and water balance change, and daily calorie estimates are uncertain.
How do I enter a deficit?
Enter it as a negative number, such as −400.
Is 7,700 kcal exact?
No. It is a simplified planning conversion, not a fixed biological law.
Can I use this for very long periods?
Long projections become less reliable because the body adapts and behavior changes.
Why does the scale move faster at first?
Early changes may include water and glycogen shifts, especially after dietary changes.