How to Measure for a G Cup Bra

Use a flexible tape that has not stretched. Stand naturally, avoid holding your breath, and check the side and back in a mirror. Thick padding and bulky clothing change the circumference you record.

Place the tape immediately below the breast tissue. It should sit level around the ribcage and feel snug without digging in. Record the number before moving the tape, then repeat once. A large difference between repeats is a reason to check the angle and tension.

Let the tape pass around the fullest point without flattening tissue. Check that it does not rise across the back. Record and repeat; do not tighten the tape merely to reach a familiar cup result.

Projection, asymmetry and soft tissue can make standing measurements less informative. A more detailed fitting may compare standing, leaning and lying bust measurements along with different underbust tensions. Our two-measurement tool does not claim to reproduce that process.

If a repeat differs substantially, check the tape across your back first. A diagonal path measures a different circumference. Next check tension: pulling the fullest-bust tape into tissue changes the reading, while leaving a gap around the ribcage makes the underbust less useful. Repeat in a natural posture rather than deliberately lifting the chest.

Write the unit next to each number. A tape with inches on one side and centimetres on the other is an easy source of confusion. Check the zero end and read at the overlap, not at the edge of a fastening or metal tab that sits before zero.

Bring your two measurements, the system used for your current bra, and observations about a specific garment. “The 34 band stays level, but the wire sits below the breast crease” gives a fitter more to work with than “G seems too big.” Describe where the bra feels comfortable as well as where it fails.

Do not average a set of obviously inconsistent readings to make them look more precise. Resolve tape position and tension first. If measuring is difficult, an individual fitting can be more helpful than repeating an uncomfortable process.

Compare the two raw underbust readings and calculate a starting size for each; do not average away an unexplained difference.

A tool result cannot guarantee garment fit.

The requested inputs are first underbust reading, repeated underbust reading, full bust. Keep the unit or chart context with the result. Blank inputs are not treated as zero, and unsupported values should be corrected rather than used to produce a convenient-looking answer.

Prepare a flexible measuring tape and identify its zero mark before wrapping it around you. Check whether the scale is inches or centimetres, then use that same side for both readings. A rigid ruler or an elastic piece of fabric does not follow the same measuring method.

A mirror or assistance can help you check the path across your back without twisting your torso. For the snug underbust, let the tape contact the ribs directly below the tissue. At the fullest bust, avoid pulling it into the tissue. Read the overlap without changing the tape position to bring it into view.

If two readings disagree, troubleshoot the measuring setup before averaging them. A change in angle, tension or posture is not random noise that arithmetic can necessarily remove. The repeat tool shows how the measurements affect the estimate so you can decide whether to measure again or seek a fitting.