Separate the trend from daily noise
Weight-Loss and Weekly Trend Calculator
Paste dated weights to calculate total percentage change, a regression-based weekly trend and the difference between your first and latest measurements.
Dated entrieskg or lbWeekly regressionNo account required
Enter your information
Paste your weight history
Use YYYY-MM-DD and a number. Entries can be daily or weekly and do not need perfectly even spacing.
For the cleanest signal, weigh under similar conditions. Sodium, carbohydrate, bowel contents, menstrual cycle, travel and hard training can move scale weight without matching fat change.
Calculated result
Trend summary
Regression-based weekly trend−0.47 kg/week−0.51% of starting weight per week
Total change−3.3 kg
Percentage change−3.59%
Time covered49 days
Eight valid measurements were used. The trend is more informative than the latest single weigh-in.
Percent change: (88.7 − 92.0) ÷ 92.0 × 100 = −3.59%
How to use the answer
Use averages and slopes to avoid reacting to water weight
The calculator uses all valid dated entries in a least-squares trend line. That makes one unusually high or low measurement less influential than simply comparing two days.
Total percentage change
(latest − first) ÷ firstUseful for milestones and for comparing change across people of different starting sizes.
Weekly slope
All measurementsRegression estimates the direction and speed across the full time window.
Context still matters
Weight ≠ body fatRapid early changes can include glycogen, water and gastrointestinal contents.
Important limitations
What the number can—and cannot—tell you
Should I enter daily or weekly weights?+
Either works. More measurements can improve the trend if conditions are reasonably consistent, but daily numbers should not drive daily decisions.
Why is the regression rate different from first-to-last change?+
The regression uses every measurement. First-to-last change can be distorted when either endpoint is unusually high or low.
Does a faster rate mean better progress?+
No. Sustainability, symptoms, nutrition, strength, lean mass and medical context matter. This calculator describes change; it does not set a safe target.