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Weight Loss Percentage Calculator

Find out what percentage of your body weight you have lost. Enter your starting weight and your current weight in pounds, kilograms or stone; the calculator also shows the weights that would mark a 5% and a 10% loss from your starting point.

Quick examples
Your numbers stay in your browser. Nothing is uploaded.
Weight lost7.5%
Amount lost
15 lb
Weight at a 5% loss
190 lb
Weight at a 10% loss
180 lb

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    Results you calculate here are kept on this device so you can come back to them.

      Formula

      Weight lost % = (starting weight − current weight) ÷ starting weight × 100
      Weight at a 5% loss = starting weight × 0.95
      Weight at a 10% loss = starting weight × 0.90

      How to use it

      1. Enter the weight you started at.
      2. Enter your weight now, in the same unit.
      3. Read the percentage lost and the amount, and see how far you are from the 5% and 10% marks.

      Worked examples

      From 200 lb down to 185 lb

      Weight lost
      7.5%
      Amount lost
      15 lb
      Weight at a 5% loss
      190 lb
      Weight at a 10% loss
      180 lb

      From 90 kg down to 81 kg

      Weight lost
      10%
      Amount lost
      19.8 lb
      Weight at a 5% loss
      188.5 lb
      Weight at a 10% loss
      178.6 lb

      Why percentage is a fairer measure

      Ten pounds is a much bigger change for someone who starts at 150 lb than for someone who starts at 300 lb. Percentage of starting weight puts people of different sizes on the same scale, which is why group challenges and clinical studies report it.

      Health guidance often frames goals this way too: a loss of 5% to 10% of starting weight is commonly cited as enough to bring measurable improvements in blood pressure, blood sugar and cholesterol for people who are overweight.

      This is an estimate for general information, not medical advice. Talk to a doctor or other qualified clinician before making health decisions based on it.

      Questions people ask

      How do I calculate weight loss percentage?

      Subtract your current weight from your starting weight, divide by the starting weight and multiply by 100. From 200 lb to 185 lb is 15 ÷ 200 × 100 = 7.5%.

      How much is 5% of my body weight?

      Multiply your weight by 0.05. At 200 lb that is 10 lb, so a 5% loss brings you to 190 lb; at 90 kg it is 4.5 kg.

      What if my weight went up?

      The result is shown as a negative percentage. From 180 lb to 189 lb is −5%, meaning a 5% gain.

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