Weight Loss Percentage Calculator

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Weight Loss
Percentage Calculator
Track your journey with precision — calculate loss %, BMI, weekly pace, set goals, and log your history. Works in kg, lbs & stone.
Your measurements
kg
kg
cm
wks
Enter your weights above to see your results instantly
BMI reference
Underweight
< 18.5
Healthy
18.5 – 24.9
Overweight
25 – 29.9
Obese I
30 – 34.9
Obese II+
35+
Goal weight planner
kg
kg
Weekly loss rate: 0.5 kg/week
0.5
Slow (0.1)◆ Healthy zoneFast (2.0)
Enter a starting and target weight above
Progress log
  • No entries yet — calculate and save your results from the Calculator tab
The formula
(starting weight − current weight)
─────────────────────────────────── × 100 = % lost
       starting weight

Example: Start 90 kg, now 81 kg →
(90 − 81) ÷ 90 × 100 = 10% lost

What is a healthy weight loss percentage?
For people with overweight or obesity, losing 5–10% of total body weight is clinically significant and can reduce risk of type 2 diabetes, heart disease, and high blood pressure. There's no universal "right" number — what matters most is sustainable, steady progress tailored to your individual situation.
Why does weight loss stall?
As you lose weight your body adapts — metabolism slows, hunger hormones increase, and calorie needs decrease. This is a normal biological response, not failure. Plateaus often resolve with a change in stimulus: adjusted calorie intake, more protein, strength training, or a brief diet break. Hormones, sleep quality, and stress levels also play a major role.
What's a good % to lose per week?
Aim for 0.5–1% of your body weight per week. For a 90 kg person that's roughly 0.45–0.9 kg/week. Faster loss (above 1.5%/week) increases risk of muscle loss, nutrient deficiencies, gallstones, and metabolic adaptation that makes long-term maintenance harder.
How do I track progress beyond the scale?
The scale is just one data point. Track how clothes fit, monthly progress photos, energy and sleep quality, workout performance (strength, endurance), and waist circumference. Body weight naturally fluctuates 1–3 kg daily due to water, food, and hormones. Weigh consistently (same time of day, fasted) and use a 7-day rolling average for trends.
Does BMI reflect health accurately?
BMI is a useful population-level screening tool but has real limitations. It doesn't distinguish muscle from fat, doesn't account for bone density, age, sex differences, or fat distribution. An athletic person can have a high BMI with low body fat. Use it as one rough indicator alongside waist circumference, blood markers, and how you feel.
Why you might struggle to lose weight
Common barriers include: eating too little (triggering metabolic adaptation), poor sleep (elevating ghrelin and cortisol), high chronic stress, underlying thyroid or hormonal issues, medications, and all-or-nothing mindset patterns. If you're doing "everything right" and not progressing, a healthcare provider can rule out physiological causes.