Track body measurements over time
A body measurement tracker records key body measurements over time — like waist, hips, chest, and arms — so you can monitor changes in body composition that a scale alone won't show. It's especially useful during strength training or body recomposition, when weight may stay stable while measurements shift.
This tracker saves each entry (date, weight, and any of body fat, chest, waist, hips, thighs and arms) in your own browser's local storage, and shows the change between your first and latest entry for each field. Nothing is sent to a server, so the history stays on this device and browser. The flip side is that clearing site data, using a private window or switching devices starts you from an empty log.
Change = Current Measurement − Previous Measurement (tracked per body part over time)
| Calculation | Expression | Result |
|---|---|---|
| Waist over four weekly entries | 34.0, 33.5, 33.0, 32.5 in | change of −1.5 in |
| Weight over the same weeks | 180, 179.5, 179, 179 lb | change of −1.0 lb |
Scale weight doesn't distinguish between fat, muscle, and water, so it's possible to lose fat and gain muscle with little or no change on the scale — measurements can reveal that body recomposition even when weight is stable.
Every 2-4 weeks is typically enough to see meaningful trends without over-focusing on short-term fluctuations that don't reflect real change.
Typically at the navel, or at the narrowest point of the torso, keeping the tape horizontal and snug but not compressing the skin.
Hydration, food intake, sodium, hormonal cycles, and time of day all cause normal short-term fluctuations of up to an inch or more in some areas — this doesn't reflect real fat or muscle change.
Either works — what matters is staying consistent with the same unit and the same measuring method each time so your tracked changes are accurate and comparable.
In your browser's local storage on the device you are using. There is no account and nothing is uploaded, so the log disappears if you clear site data, use a private window or open the page on another device.