Interdialytic Weight Gain Tracker
Use the previous post-session weight and the current pre-session weight.
Your between-session weights inputs
Descriptive weight arithmetic.
Between-session weights report
1.9 kg · signed between-session change
Reference denominator 70 kg; no fluid-removal prescription
Full result table
| Weight role | kg |
|---|---|
| Previous post-session | 70.2 |
| Current pre-session | 72.1 |
| Supplied comparison | 70 |
Descriptive weight arithmetic. Weight change is not automatically all fluid, and this tool does not prescribe ultrafiltration, removal rate, target weight or fluid restriction.
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How to use Interdialytic Weight Gain Tracker
- Use the previous post-session weight and the current pre-session weight.
- Subtracting previous from current can produce a positive or negative result.
- Between-session change compares the two measured weights.
Worked example
72.1 minus 70.2 kg is 1.9 kg; relative to a 70 kg comparison this is 2.7143%.
Formula, accuracy & limitations
Signed between-session change = current pre-session minus previous post-session weight. Percentage = change / supplied comparison weight × 100. Current-to-comparison difference is a separate value.
Descriptive weight arithmetic. Weight change is not automatically all fluid, and this tool does not prescribe ultrafiltration, removal rate, target weight or fluid restriction.
The primary result is rounded to two decimal places. Calculation tables show up to four and supporting metrics up to six. Very small nonzero values use scientific notation. Display rounding is not fed back into the arithmetic.
Pair the intended two measurements
Use the previous post-session weight and the current pre-session weight. They have different roles from a prescribed comparison weight, so each field is named explicitly. Use comparable scales, clothing and measurement conditions where possible rather than expecting the calculator to correct them.
Keep the sign of the change
Subtracting previous from current can produce a positive or negative result. The engine preserves that direction. Dividing the signed difference by the entered comparison weight gives a percentage with a visible denominator, not a hidden definition of dry weight.
Distinguish two different gaps
Between-session change compares the two measured weights. Current-to-comparison gap instead compares the present measurement with the supplied reference. These can differ, and neither is silently renamed a prescribed removal volume. The daily change is descriptive arithmetic over the entered interval.
Avoid turning the result into a dialysis prescription
Body mass can change for reasons other than fluid. Treatment settings depend on clinical context not present here. This report does not select ultrafiltration, recommend fluid restriction or decide whether a session should proceed; it makes the entered weight comparisons easier to review.
Frequently asked questions
Why are there three weight fields?
Two are actual measurements around the interval. The third is a supplied comparison denominator, which is not automatically set equal to either measurement.
Can the result be negative?
Current pre-session weight below the previous post-session weight produces a negative signed change. The engine preserves it.
Is weight gain the same as fluid to remove?
The worksheet does not make that assumption. It provides no ultrafiltration volume or removal-rate prescription.
What does the percentage denominator use?
The signed between-session change is divided by the entered prescribed comparison weight, then multiplied by one hundred.
