The Monthly Weight Estimator projects an end-of-month body weight from your current weight, the number of days in the tracking period, and an expected weekly gain or loss. It is useful for planning and reviewing a gradual trend rather than predicting day-to-day scale readings. The result shows the projected weight and total change over the selected period. Actual weight can move differently because of hydration, digestion, training, illness, medication, and other factors, so use the estimate as a planning reference rather than a guaranteed outcome.
1. Enter starting weight
Use the weight measured at the beginning of the period.
2. Enter the weekly trend
Use a negative value for loss and a positive value for gain.
3. Set the period length
Choose the number of calendar days you want to project.
4. Review the estimate
Compare projected weight with your actual trend and revise the weekly assumption when needed.
Projected weight = Starting weight + (Weekly change × Days ÷ 7)
Weekly change is signed: a loss is negative and a gain is positive. The calculation assumes a steady linear trend throughout the period.
The main result is the weight you would reach if the entered weekly trend continued evenly for the chosen number of days.
Short-term scale changes often reflect water and food mass, so compare averages or consistent weigh-ins instead of relying on one reading.
Given: Starting weight 180 lb, weekly change −1 lb, and 30 days.
Calculation: 30 ÷ 7 = 4.2857 weeks. Change = −1 × 4.2857 = −4.2857 lb. Projected weight = 180 − 4.2857 = 175.71 lb.
Result: The estimated end-of-month weight is 175.71 lb.
Yes. Enter a negative weekly change for loss and a positive value for gain.
Body water, sodium, glycogen, digestion, and measurement timing can create short-term variation that a linear estimate does not model.
The page is labeled in pounds. The math is unit-neutral, but all weight entries and outputs must use the same unit.
Recalculate with a revised weekly change or split the month into separate periods and combine the changes.
No. It projects total scale weight only and does not determine how much change comes from fat, muscle, or water.