Getting the entries in
One line per weigh-in: 08/27/2026 178.4. Dates take MM/DD/YYYY or YYYY-MM-DD, with dots or slashes as separators. To keep body composition alongside, add columns: 08/27/2026 | 178.4 | 21.5 | 71.2 is weight, body fat percentage, muscle mass. Columns split on a vertical bar, a tab or plain spaces, so an export from a scale app usually pastes in without editing. Repeat a date and the entries for that day are averaged into one point. Order does not matter, since everything is sorted before anything is calculated.
Why the moving average is the number to watch
Scale weight swings by a pound or two within a single day, driven by food and drink still in transit, salt, whether you have been to the bathroom, and for many people the point in a menstrual cycle. Compare yesterday to today and you are reading that noise, not the trend. Averaging several days lets the swings cancel and leaves the drift. Seven days is the usual choice because it covers a full week of habits — the takeaway on Friday, the long run on Sunday — rather than a slice of one. The moving average column here covers the entries within the window ending on that date, so during a gap in weighing it may be built from only one or two numbers; the entry count next to it tells you when that is happening.
Rate, projection, flat stretches
The weekly rate is the change in the moving average divided by the number of weeks it took. Two are shown: one across the whole log and one across roughly the last four weeks, which move apart when something has changed recently. The target projection extends those rates in a straight line, which is the projection's whole weakness — the same routine usually yields less as the weight comes down, so arrival tends to be later than the estimate. Flat stretches are marked where the moving average stayed inside a narrow band for two weeks or more, and a flat stretch on a chart can just as easily be a stretch of missed weigh-ins or a change in when you stepped on the scale.
What this page will not tell you
It reports averages, differences, a rate and a straight-line projection. It does not say whether any of that is good, appropriate or safe for you, because that depends on things a list of numbers does not contain. The pace that is right for one person is wrong for the next, and weight that moves noticeably without anyone intending it to is a reason to talk to a clinician rather than to open a spreadsheet. Take the arithmetic; leave the interpretation to the person who knows your history.
Questions people ask
When should I weigh myself?
There is no single right time, but there is a wrong approach, and that is varying it. Morning, after the bathroom, before eating, in about the same amount of clothing gives the most comparable numbers. Evenings work too, but that day’s food and drink are still on board, so the numbers run higher and swing wider. Consistency matters far more than which slot you pick.
I skipped several days and the average looks odd.
The moving average only sees entries inside its window, so after a gap it may be resting on one or two numbers and the noise comes straight through. A blank in the average column means there was a single entry in that window. Rather than back-filling guesses, weigh in more often for a week or so and the average settles again by itself.
Is anything saved?
No. It all runs in your browser, nothing is transmitted, and refreshing clears the box. Copy the text output into a note to carry the log forward — it pastes straight back — or print the sheet and use the blank rows at the bottom to keep going on paper.