You need only a soft measuring tape, a few quiet minutes and a relaxed posture. The goal is a repeatable body measurement — not to pull the tape as tight as possible or force the result toward a particular label.
Measurement guide
Measure privately, repeat the numbers, then use the exact manufacturer chart.
Two useful measurements
Underbust: around the torso directly beneath the breast area. Bust: around the fullest part of the chest/bust, with the tape level around the body.
Before you measure
- Use a flexible cloth or sewing tape.
- Measure over bare skin or a very thin, non-padded layer when practical and comfortable.
- Stand naturally and breathe normally.
- Keep the tape parallel to the floor.
- Do not compress the body to chase a smaller number.
How to measure the underbust
- Place the tape directly beneath the breast area and around the rib cage.
- Check in a mirror or ask a trusted helper to confirm the tape is level.
- Bring the tape snugly against the body without digging in.
- Record the measurement.
- Repeat once. If the readings differ noticeably, measure again.
How to measure the bust
- Move the tape around the fullest part of the chest/bust.
- Keep it level across the back.
- Let the tape rest against the body without flattening or compressing.
- Record and repeat the measurement.
What to do with the numbers
Use the measurements with the specific manufacturer's current chart for the exact bra or product family. If a chart asks for only one measurement, follow that chart's instructions. If it uses apparel sizing, compare the stated body-measurement ranges rather than assuming the wearer's normal shirt size will always match.
Common measuring errors
| Error | Why it matters | Better approach |
|---|---|---|
| Tape slopes up/down | Changes circumference | Keep it level around the torso |
| Pulling very tight | Can understate the body measurement | Snug, not digging |
| Measuring over bulky clothing | Adds volume | Use a thin layer |
| Using an old measurement | Growth and body changes are normal | Remeasure when fit changes |
Make measuring comfortable and private
For a first-time wearer, privacy can matter as much as technique. The wearer can often measure independently in front of a mirror. If help is wanted, ask permission before adjusting the tape or clothing. There is no reason to turn measuring into a public event.
Why repeating the measurement matters
A tape can shift, twist or be pulled more tightly on the second pass. Two similar readings increase confidence that the measurement is usable. If the numbers differ substantially, reset the tape and take a third reading rather than averaging obviously inconsistent measurements.
Inches versus centimetres
Record the unit with the number. Manufacturer charts may use inches, centimetres or both. A number without a unit is easy to misread later, especially when comparing brands.
Measurements are inputs, not a diagnosis
Traditional bra-size formulas can differ across retailers and regions. TrainingBras.com therefore does not turn two measurements into a supposedly universal size. We use the measurements to identify the range specified by the manufacturer, then rely on fit.