How to measure yourself for reps

Body measurements versus flat measurements

A body measurement describes you: chest circumference 100 cm. A flat measurement describes a garment lying flat: chest across 52 cm. A listing almost always publishes flat numbers, because that is what a tape on a table produces.

So before comparing anything, double the flat number. A 52 cm flat chest is 104 cm around, which gives about 4 cm of ease over a 100 cm body. If you skip that step you will read 52 as your number and order two sizes too small.

Taking your own numbers

Use a soft tape, wear thin clothing, and keep the tape level. If you are measuring yourself, do it in front of a mirror, because a tape that slopes at the back adds centimetres that are not there.

Measure three times and take the median rather than the maximum. Most people unconsciously pull the tape snug on the second attempt, and the median filters that out.

• Chest at the fullest point, tape level under the arms
• Shoulder from the bone at one side to the bone at the other
• Sleeve from the shoulder bone to the wrist bone
• Natural waist at the narrowest point, not at the trouser line
• Hip at the fullest point
• Inseam from the crotch to the floor, barefoot

Ease is where the size is decided

Ease is the difference between the garment and your body. A fitted tee might have 2 to 6 cm of ease; an oversized one might have 15 cm or more. The same body measurement produces different sizes depending on the intended fit.

The reliable method is to measure a garment you already own and like, then look for a listing whose flat numbers match it. That bypasses the question of fit language entirely, because your own shirt already embodies the fit you want.

Shoes need a different method

Foot length in centimetres is more reliable than any shoe size, because Chinese, EU and US numeric scales do not convert cleanly. Stand on a sheet of paper with your heel against a wall, mark the longest toe, and measure in the evening when your foot is largest.

Then compare with the listing's centimetre chart and its insole length if published. Two feet differ, so measure both and use the longer one. A half size of extra room is usually better than a tight fit you cannot return cheaply.

Applying it to an order

For each item, write down four things: the listing's flat chest, its shoulder, its length, and your target from a garment you own. If shoulder matches and chest is within a few centimetres, order it. If shoulder is too narrow, no amount of chest ease will fix the look.

Ask the agent to confirm a measurement on the actual item if the listing numbers look inconsistent. Warehouse staff measure items routinely, and a 3 cm discrepancy between listing and reality is worth catching before export.

Record it once and stop re-measuring

Keep a short table of your own numbers, plus a row for each garment you own and like. After that, every sizing decision is a lookup rather than an experiment.

This is the least glamorous and most valuable page on the site. Our related sizing pages go deeper into clothing charts and shoe conversion, and the oopbuy style measurement sheet, with your body numbers at the top and garment rows below, is exactly the tool that makes the next ten orders boring in the best way.

Borrow the numbers from a garment

If you can, have someone else take the shoulder and sleeve numbers. Measuring your own back is where most errors come from, because the tape sits where you can reach rather than where the seam actually is.

Failing that, measure a garment instead of a body. A shirt that already fits you encodes every number you need, including the ease you like, and it does so without a tape, a mirror or a second person. It is also the same number the listing will quote, which removes a conversion step entirely.