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Weight Loss Percentage Calculator

Work out weight loss percentage instantly with clear inputs, formula shown and shareable results.

About Weight Loss Percentage Calculator

Percentage weight loss is the standard clinical measure because it scales with body size: 9 kg from 95 kg is 9.5%, which matters more than the absolute figure. A 5% loss already improves blood pressure and insulin sensitivity, and 10% is the usual target in obesity management guidelines.

Formulas

Percentage lost

percent = (start - current) / start x 100

Clinical milestones

5% meaningful, 10% target, 15% substantial

Worked example

With the default values below, Weight Loss Percentage Calculator returns Weight Lost of 9.47%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Starting weightminimum 0 kg
95 kg
Current weightminimum 0 kg
86 kg

Results

Weight Lost
9.47%
Absolute Weight Lost
9.00 kg
Current Weight As A Share Of Starting Weight
90.5%
Clinical Milestone
Past the 5% milestone, where health benefits begin

Step by step

  1. 1Values used
  2. 2Percentage lost
  3. 3Clinical milestones
  4. 4Weight Lost= 9.47
  5. 5Absolute Weight Lost= 9.00 kg
  6. 6Current Weight As A Share Of Starting Weight= 90.5
  7. 7Clinical Milestone= Past the 5% milestone, where health benefits begin

Assumptions and limits

  • The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.
  • This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.

Frequently Asked Questions

Why use percentage rather than kilograms?

Because 5 kg means something very different at 60 kg than at 150 kg. Percentage makes outcomes comparable and matches how trials report results.

What loss rate is safe?

About 0.5-1% of body weight a week. Faster rates increase lean mass loss and are harder to sustain.

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