Weight Loss Percentage Calculator
Progress as a share of where you started — the figure clinicians actually use.
Your weights
Progress
Why percentage beats kilograms
Ten kilograms means something different at 150 kg than at 65. Expressing loss as a share of starting weight makes progress comparable between people and across time, which is why clinical research reports it that way almost universally.
The threshold that matters is 5%. Losing 5-10% of starting body weight is associated with measurable improvement in blood pressure, blood glucose, triglycerides and sleep apnoea — and those benefits appear well before anyone reaches a "goal" weight or a normal BMI. It is the most useful and least appreciated number in weight management, because it reframes a 7 kg loss from "barely started" to "clinically meaningful".
Two cautions on reading the figure. Not all of it is fat: early loss includes water and glycogen, and a rapid drop in the first fortnight is mostly not fat tissue. And weight fluctuates by a kilogram or more day to day from hydration, sodium, glycogen and digestive contents, so judge progress on a trend across two to four weeks rather than on single readings.
Medical disclaimer. This calculator is for general information and education only. It is not medical advice, not a diagnosis, and not a substitute for professional care. Rapid or unexplained weight loss, and any weight change during pregnancy or alongside an eating disorder, warrants clinical advice rather than a calculator.Speak to a doctor or another qualified clinician about any health decision.Last reviewed .
Frequently asked questions
How do I calculate weight loss percentage?
Divide the weight lost by your starting weight and multiply by 100. Losing 7 kg from 95 kg is 7 ÷ 95 × 100, which is about 7.4%.
Why is 5% considered significant?
Because measurable health improvements appear there — blood pressure, blood glucose, triglycerides and sleep apnoea all typically improve with a 5-10% loss, long before reaching any target weight. It is the threshold most clinical guidance uses.
Is weight loss percentage better than kilograms?
For comparing progress, yes. Ten kilograms is a very different achievement at 150 kg than at 65 kg, and percentage makes the two comparable. Kilograms are still the more practical figure for day-to-day tracking.
Why has my weight not moved this week?
Normal fluctuation from hydration, sodium, glycogen and digestive contents easily spans a kilogram or more, which masks genuine fat loss over short periods. Look at the trend across two to four weeks instead.
Is all the weight I lost fat?
No, particularly at the start. Early loss includes water and glycogen — each gram of glycogen holds roughly three grams of water — which is why the first fortnight often shows a drop that later slows.