The essentials
The math behind the result
(Current − starting) ÷ starting × 100
Subtract the starting measurement from the current one, divide by the starting measurement, then multiply by 100. The starting value is the reference point. Reversing the two inputs changes the calculation, so keep the earlier measurement in the starting field when describing change over time.
| What you see | What it means |
|---|---|
| Negative percentage | The current measurement is lower. |
| Positive percentage | The current measurement is higher. |
| Zero | The two measurements match. |
The essentials
Keep the comparison consistent
Enter both weights in pounds or both in kilograms. Do not mix units. The starting weight must be greater than zero because the formula divides by it. The tool uses the values you enter before rounding the displayed percentage to two decimal places.
| Illustrative example | Calculation |
|---|---|
| Starting measurement | 200 lb |
| Current measurement | 190 lb |
| Change | −10 ÷ 200 × 100 = −5% |
The example describes a 5% decrease from the starting measurement. If the same two measurements are reversed, the increase is about 5.26% because the denominator is now 190. Both calculations can be correct; they answer different questions. Neither is a forecast.
The essentials
What the percentage leaves out
Put it in context
This percentage does not explain why weight changed or whether a change is appropriate for you. It is not a target or treatment prediction.
Start here · one question
What's your goal weight?
Choose a goal to discuss with your clinician. You can change it in your intake.
Save the measurement dates alongside the numbers so someone reading the result knows the time period. For a clinical conversation, add any relevant symptoms or medication changes to the symptom and medication discussion log. The percentage alone cannot supply that context.
