Last updated: September 15, 2025
How to Calculate Weight Loss Percentage
Quick answer: Weight-loss % = (Starting Weight − Current Weight) ÷ Starting Weight × 100. Use the calculator below for instant results, weekly pace, and progress to goal. Then see the examples and tips to keep your momentum going.
Weight-Loss Percentage Calculator
Your Results
Enter your numbers to see weight-loss %.
Your data is calculated in your browser—nothing is sent anywhere.
The Formula (With Examples)
Weight-loss % = (Starting − Current) ÷ Starting × 100. Units don’t matter (lb or kg) as long as both are the same.
- Example: Start 185 lb → Current 172.5 lb. Change = 12.5 lb. % loss = 12.5 ÷ 185 × 100 = 6.8%.
- Example (kg): Start 84 kg → Current 80 kg. Change = 4 kg. % loss = 4 ÷ 84 × 100 = 4.8%.
What’s a Healthy Pace?
- Many people do well with ~0.5–1.0% of body weight per week at most, or about 0.5–2.0 lb/wk (0.2–0.9 kg/wk) depending on size and context.
- Protein & strength help preserve muscle while losing fat. See our Top 10 Health Tips.
- Use our Calorie Calculator to set a small, sustainable deficit and adjust using 10–14 day averages.
Troubleshooting Stalls
- Track for 7–10 days (weekends too). Measure oils, dressings, nut butters.
- Average your scale weight across the week to smooth water shifts (sodium, hormones, soreness).
- Adjust one dial: reduce portions by ~100–200 kcal/day or add 2–3k steps/day. Re-check in 10–14 days.
- Hydrate smart: alternate plain water with a light electrolyte mix—see Electrolytes: Best Water Supplements.
Related Reading
- Calorie Calculator: Find Your Daily Needs
- How Long Does It Take to Notice Weight Loss?
- Carbs & Weight Loss: Make Them Work
- Are Protein Bars Good for Weight Loss?
- Healthy Lifestyle Hacks
FAQs
How do I calculate weight-loss percentage?
Use (Starting − Current) ÷ Starting × 100, or the calculator above.
Does it matter if I use lb or kg?
No. Percentage is unit-agnostic—just use the same unit for both numbers. You can switch units in the calculator at any time.
What’s a good weekly loss?
About 0.5–1.0% of body weight per week works for many people. Smaller, steadier changes are easier to maintain.
How often should I weigh in?
Daily or a few times per week, then use a 7–10 day average to smooth normal water fluctuations.
Why did my % jump without changing food?
Water shifts from sodium, soreness, menstrual cycle, and sleep can move the scale a few pounds. Look at weekly averages, not single days.
Disclaimer: This page is for general information only and isn’t medical advice. If you have medical conditions or take medications that affect fluids or appetite, work with your clinician.
