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Tape measurements

Waist, chest, arms and what to compare.

Tape measurements are a monthly set of six readings with a tape measure: waist, neck, chest, upper arm, thigh and hips. One sitting a month is enough, because a tape does not move fast and what matters is the change between months.

When to use it

  • You want a second, independent sign of fat loss while the scale seems stuck.
  • You want to follow arms, thighs or chest over months without new equipment.
  • You have no smart scale and want a way to judge change anyway.
  • You want a reminder so the tape happens each month.

Step by step

  1. On Progress, tap the Body row, then Tape measurements. You can also get there from History & reports, then Measurements.
  2. Tap Take your first tape, or Add measurements next time. A full tape is all six sites in one sitting, once a month.
  3. For each site, the form shows a short instruction underneath. Measure and type the number in centimetres; Forma reads either a decimal point or a comma.
  4. Skip any site you could not measure, and Save anyway. The entry is kept, but a partial entry does not reset the monthly clock and does not count as this month's full tape.
  5. Once a site has two or more readings, a chart appears for it. Touch the chart and slide your finger along it to read the value on any date. Below that, the History list shows your past entries, each labelled "Full tape" when all six sites are in it.

The six sites

Each site has a fixed instruction so the next tape measures the same thing:

SiteHow to measure
WaistAt the navel, tape level all the way round, at the end of a normal breath out. Not pulled tight, not slack.
NeckJust below the larynx, tape sloping slightly down at the front.
ChestAround the fullest part, relaxed.
Upper armFlexed, midpoint between shoulder and elbow.
ThighStanding, midway between hip crease and knee.
HipsAt the widest point, feet together.

The screen shows each site's instruction while you type, so you do not have to memorise this.

What to compare

  • The screen lists your latest reading for each site, next to the change over the last roughly three months. Read the direction of that change, not the exact millimetre.
  • Compare like with like: same site, same tape, same technique. The instructions exist so that today's waist and next month's waist measure the same thing.

The tape's own body-fat estimate

Waist and neck also give a body-fat estimate, the US Navy formula; for women the hips count in it too. The estimate is a second opinion next to your other readings. The scale or a clinic scan is preferred, and the tape estimate never replaces them. When a scale or a clinic scan has answered within the last few weeks, the neck field moves out of the way, because the neck is only needed for the tape's own estimate. A button offers to add it back if you want a full tape.

Good to know

The monthly clock. A full tape resets the counter for 28 days. Forma tells you where you stand: "No full tape yet", "Next full tape in N days", or "A full tape is due. It has been N days."

Plausible ranges. Each field checks a sensible range for the site, for example waist 50-200 cm. A value outside that range is flagged straight away, so a mistyped number does not pollute your trend.

Something unclear or missing? Write to and say which page.