Free progress tool

Weight Loss Percentage Calculator

Enter your starting and current weight to see how much you have lost as a percentage of where you began, and at what pace if you tell it how long it took.

Worked example

Going from 75 kg to 70 kg is 5 kg lost, which is 6.7% of the starting weight, or 0.42 kg a week over 12 weeks.

Calculate your weight loss percentage

The result below starts from the example's numbers. Change any field and it updates as you type.

Starting weight (kg)

Current weight (kg)

Weeks it took, optional (weeks)

Lost (% of starting weight): 6.7%
Lost: 5kg; 11 lb
Per week: 0.42kg/week; 0.56% of starting weight

What common percentages of your starting weight come to
Percent lost	Weight lost (kg)	Weight then (kg)
5%	3.8	71.3
10%	7.5	67.5
15%	11.3	63.8

The percentage is the change divided by your starting weight, so the same loss is a larger percentage the lighter you start.

Track this target every day

Use the number above as your daily goal in CalorTracker, then log meals by photo, voice or text and see where your day stands against it. Free to start, no card needed to explore.

Results are estimates from published formulas, not medical advice. Your own body can sit above or below them.

Where the formulas come from, and how we check them: how we calculate.

The formula

Percentage lost = (starting weight − current weight) ÷ starting weight × 100. Losing 5 kg from 75 kg is 5 ÷ 75 = 6.7%. Because the starting weight is the divisor, the same loss is a bigger percentage the lighter you started, which is why percentages are a fairer way to compare two people than kilograms are. If your weight went up, the same sum gives the percentage gained.

The weekly rate

If you enter how many weeks it took, the calculator divides the change by the weeks to give a weekly pace in kilograms (and pounds) and as a percentage of your starting weight. The CDC describes about 1 to 2 pounds (0.5 to 0.9 kg) a week as steady weight loss, and the page adds a note when your pace was faster than that.

Percentages of your starting weight

The table works out what 5%, 10% and 15% of your starting weight come to, and what you would weigh then. It is plain arithmetic, not a set of targets. For a goal weight and a daily calorie target, use the weight loss calculator; for how long a loss will take, the how long to lose weight calculator.

Frequently asked questions

How do you calculate weight loss percentage?

Subtract your current weight from your starting weight, divide by your starting weight and multiply by 100. For example, going from 80 kg to 72 kg is 8 ÷ 80 = 10%.

Is the percentage based on starting weight or current weight?

On your starting weight. That keeps it consistent with how much of your original body weight has gone.

What if I gained weight?

The calculator shows the percentage gained, using the same formula, and labels the result as a gain.

Is there a healthy percentage to lose per week?

The CDC describes about 1 to 2 pounds (0.5 to 0.9 kg) a week as steady weight loss. Anything faster than that is worth discussing with a doctor.