Uses the same units for both fields (lb, kg, etc.). Shows start minus goal; positive usually means weight to lose if your goal is lower.
Difference = start − goal. Positive means the goal is below the start (common “weight to lose” case); negative means the goal is above the start.
Total body-weight math only—not body fat, lean mass, timelines, or medical advice.
This weight-difference calculator applies the formulas described on this page to the values you enter. Outputs are not financial, tax, legal, or medical advice.
Last reviewed: 2026-04-17
No. It only subtracts your goal weight from your start weight in the units you enter. It does not estimate fat mass, muscle change, or health risk.
The result is a negative number (weight gain in the same units). The tool is a numeric difference only—not a diet or treatment plan.
No. It is for quick illustration only. For nutrition or medical goals, consult a qualified professional.