Weight loss percentage calculator.
Set a goal. See your progress.
Weight
Your next step,
made clearer.
Enter your details for a useful starting point.
How this tool works
Set my goal compares your current weight with a selected lower goal. The difference is divided by your current weight and multiplied by 100. Track my progress compares a recorded starting weight with your weight today, showing loss, gain or no change. Neither mode predicts fat loss, a recommended target or a timeline, or assesses whether a goal is healthy for you.
Weight fluctuates with fluid, food, digestion and other factors. Compare measurements taken under similar conditions.
This is a calculation, not proof of fat loss or muscle change.
If weight loss is unintentional, rapid or accompanied by feeling unwell, arrange a medical review.
Before you use this calculator
These tools offer general information for adults. Results are estimates, not a diagnosis, treatment plan or prescription. Your clinician can help you decide what fits your health, medicines and goals.
Your calculation happens in this browser. Do not enter your name or medical records. These tools do not assess medicine suitability or dosing.
Body-composition readings are estimates and can vary with hydration and measurement conditions. Ask the team about suitability.
Sources and context
- NICE CG32: Nutrition support for adults - recommendations
30–35 mL/kg/day fluid as nutrition-support guidance in selected adults, not a universal wellness hydration formula. Also identifies unintentional loss and inadequate intake as clinical concerns.
- WellNest: InBody scan in Cape Town
Verified availability and link; body composition and resting-energy estimates. Not evidence of individual clinical benefit.
Sources checked in the supplied release pack on 18 October 2026. Clinical review by Dr Addinall and compliance review by Thomas are complete.
Common questions
What do current weight and goal weight mean?
Current weight is your latest recorded measurement. Goal weight is a lower weight you choose for this comparison. The calculator shows the difference needed to reach that selected goal; it does not recommend a goal or assess whether it is healthy for you.
How is the percentage needed to reach my goal calculated?
The difference between your current weight and selected goal is divided by your current weight, then multiplied by 100. For example, a current weight of 100 kg and a goal of 90 kg represent a difference of 10 kg, or 10% of the current weight. This is a selected future difference, not weight already lost.
Does this predict fat loss or when I will reach my goal?
No. Scale weight includes fat, muscle, water and other tissues. The calculator does not predict fat loss, the pace of change or a target date. A selected goal is not automatically healthy. If weight loss is unintentional, rapid or accompanied by feeling unwell, arrange a medical review.
Does a lower weight always mean progress?
No. Strength, energy, nutrition, symptoms and your personal health goals matter too. Unintentional weight loss needs attention.
Can this tell me how much fat I have lost?
No. The scale includes fat, muscle, water and other tissues. An optional body-composition assessment can add context, but its readings are estimates too.
How should I compare measurements?
Use the same scales and similar conditions. Look at the longer-term pattern instead of judging a single reading.
Your next step
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