Built for Australian private practice
Percent weight change calculator
Compare current and usual weight using the same unit. Negative values indicate loss; positive values indicate gain.
Free to use · No signup
Your inputs
Start with this illustrative example, then replace the numbers with your own. Results update as you type.
Calculated in your browser. Your inputs are not stored or sent to analytics.
Illustrative example result
- Weight change (%)
- -5
- Weight change (input unit)
- -4
This describes change only. It does not diagnose malnutrition, distinguish fluid from tissue changes, or determine whether loss is intentional. Interpret alongside the time period and clinical assessment.
Turn your assessment into a client plan
Set client nutrition targets, build meal plans and keep consultation notes together in Notrispace.
Start your practice workspaceHow the calculation works
Weight change (%) = (current weight − usual weight) ÷ usual weight × 100. Absolute change = current − usual weight. Both inputs must use the same unit.
Worked example
A change from 80 to 76 in the same weight unit gives −4 units and −5%. A change from 80 to 84 gives +4 units and +5%.
Questions practitioners ask
What does the result mean?
Weight change (%) = (current weight − usual weight) ÷ usual weight × 100. Absolute change = current − usual weight. Both inputs must use the same unit.
Who is this calculator for?
For nutritionists, dietitians and naturopaths supporting individual client assessment and planning. Example values are illustrative, not prescribed targets.
What are the limitations?
This describes change only. It does not diagnose malnutrition, distinguish fluid from tissue changes, or determine whether loss is intentional. Interpret alongside the time period and clinical assessment.