Weight trend

Calculate your weight trend

The scale swings by a kilo or two from day to day. Add your measurements and see where your weight is really heading and how fast.

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kglb

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For example 2026-10-01 84.2 or 01.10.2026; 84.2. Lines with only a weight count as consecutive days up to today.

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How it works

Your weight is made up of what really changes and of daily swings from water, salt, meals and digestion. The calculator smooths the daily values into a trend weight. That way you see the direction without being thrown off by single outliers.

It uses the exponential smoothing that is also the default in the Lean is law app: every new daily value counts for 10 percent, the previous trend for 90 percent. In the first days it uses a running average so the trend does not stick to the first entry. On days without a measurement the trend stays put, and after a gap the next value counts correspondingly more.

The weekly rate is the slope of a straight line through the trend values of the last 14 days. It is given in kg and as a percentage of your trend weight and classified: Lean Bulk at 0.25 to 0.5% per week, Cut at 0.5 to 1.0%, Maintain at less than 0.1 kg per week. The trend lags real changes by about a week; so give every change two weeks before you judge it.

Formula and source

Trend(today) = Trend(yesterday) + α × (measurement - Trend(yesterday)), α = 0.1 Start-up: α = max(0.1; 1 / number of measurements) Gap of n days: α = max(1 - 0.9^n; 1 / number of measurements) Weekly rate = slope (regression) of the trend values of the last 14 days × 7

Exponential smoothing with 10 percent after John Walker, The Hacker's Diet (1991), as in the Lean is law app. Pace ranges after Helms E. R., Aragon A. A., Fitschen P. J., Evidence-based recommendations for natural bodybuilding contest preparation, JISSN 11, 2014 (Cut) and Iraki J. et al., Nutrition Recommendations for Bodybuilders in the Off-Season, Sports 7 (7), 2019 (Bulk).

Frequently asked questions

Because it is a weighted average of past days. While you are losing weight it usually sits above today's reading, and while gaining it sits below. This lag of about a week is the price of a calm line.

Ideally daily, in the morning after using the toilet and before breakfast. More measurements make the trend more stable. With only two or three measurements per week the smoothing works too, but takes longer to become reliable.

The trend stays put on those days. When the next measurement comes after a gap, it counts correspondingly more. Several measurements on the same day are averaged into one daily value.

No, everything runs in your browser. Only if you tick "Remember on this device" do the values stay in this browser's storage. With "Delete all data" you remove them again.

As guidelines, 0.25 to 0.5% of body weight per week applies to a Lean Bulk and 0.5 to 1.0% to a Cut. These are rough guides, not medical advice; beginners often gain muscle faster than advanced lifters.

All results are estimates and do not replace advice from a doctor or dietitian.

Related calculators

Bulk and cut calorie target Surplus or deficit from your target rate per week. TDEE calculator Basal metabolic rate and total daily energy expenditure using Mifflin-St Jeor. Body fat calculator Estimate with the US Navy tape measure method.