For one-piece swimwear, measure torso length as a loop from a shoulder point, down the front, through the legs and back up to the same shoulder point. Dress size cannot replace this measurement because it does not describe vertical torso length.
What you need
- A flexible measuring tape
- Light, close-fitting clothing
- A mirror or another person to spot a twisted tape
- A note with the date, units and method
Take the torso-loop measurement
- Stand naturally without lifting the chest or holding the stomach in.
- Choose a repeatable starting point on top of one shoulder.
- Run the tape down the front of the torso and through the legs.
- Bring it up the back to the starting point.
- Keep the tape close but not pulled tight.
- Repeat once. If the results differ, check the tape path before averaging anything.
Only compare matching definitions
Open the size guide for Army Green One Piece Plus Size Swimsuit and look for a torso, girth or loop measurement. Read the chart's own diagram or definition. If the store measures from shoulder to crotch in one direction rather than as a full loop, your loop number is not directly comparable.
Keep the rest of the size check
Bust, waist and hip measurements still matter when the chart uses them. Record each with its own method and units. Measurements narrow a size decision, but they cannot guarantee how a particular swimsuit will feel or move.