Measurements you need
Without shoes, back to the wall: heels, buttocks and shoulder blades touching the wall, head straight. Mark the crown on the wall and measure from the floor.Without shoes, back to the wall: heels, buttocks and shoulder blades touching the wall, head straight. Mark the crown on the wall and measure from the floor.
From height, the pattern maker estimates children's measurements that are hard to take: crotch length, hip depth, upper arm circumference and sleeve length.From height, the pattern maker estimates children's measurements that are hard to take: crotch length, hip depth, upper arm circumference and sleeve length.Tape horizontally across the most prominent points of the bust, at the back — slightly above the shoulder blades, under the arms. In your usual underwear, not pulled tight.Tape horizontally across the most prominent points of the bust, at the back — slightly above the shoulder blades, under the arms. In your usual underwear, not pulled tight.
Usually 31½–51⅛ in.Usually 80–130 cm.Tape horizontal around the narrowest part of your torso, usually ¾–1⅝ in above the navel. Snug but not tight; don't pull in your stomach.Tape horizontal around the narrowest part of your torso, usually 2–4 cm above the navel. Snug but not tight; don't pull in your stomach.
Usually 22⅞–43¼ in.Usually 58–110 cm.Tape horizontal around the fullest part of your buttocks, allowing for the curve of your stomach. Stand straight, feet together.Tape horizontal around the fullest part of your buttocks, allowing for the curve of your stomach. Stand straight, feet together.
Usually 33⅛–51⅛ in.Usually 84–130 cm.Tilt your head: a prominent vertebra can be felt at the base of the neck at the back. Tape from it down along the spine to the waist tape.Tilt your head: a prominent vertebra can be felt at the base of the neck at the back. Tape from it down along the spine to the waist tape.
Usually 14⅝–17⅜ in.Usually 37–44 cm.The key measurement for a one-piece swimsuit. Tape from the mid-shoulder down through the bust, between the legs and up the back to the same point on the shoulder. Stand straight, don't pull the tape tight. Without this measurement the pattern maker will estimate it from the back length and circumferences.The key measurement for a one-piece swimsuit. Tape from the mid-shoulder down through the bust, between the legs and up the back to the same point on the shoulder. Stand straight, don't pull the tape tight. Without this measurement the pattern maker will estimate it from the back length and circumferences.
Usually 55⅛–68⅞ in.Usually 140–175 cm.How the swimsuit is drafted
The front and back widths are a quarter of the bust, waist and hip measurements multiplied by the fabric stretch factor (0.9 for medium stretch). Lengthwise, the swimsuit is 10% shorter than the body. The pattern maker estimates the rise, hip depth, upper arm circumference and sleeve length from height using standard body measurements tables for girls. The sleeve is as wide as the upper arm circumference plus ⅜ in1 cm, and the sleeve cap length equals the armhole with no ease: knit fabric doesn't need it.
We checked the draft against proven commercial patterns for the same style: the key measurements match.
The pattern maker checks the draft itself: the circumferences under the armhole and at the waist, matching side and shoulder seams, the inseam, the length along the torso, the leg opening, whether the head fits through the neckline, and the sleeve cap against the armhole. The results appear in the "Draft check" section.
How to print and tape
Download the PDF on Letter or A4 sheets and print at 100% scale, without "fit to page". The first sheet has the test square: measure it with a ruler. The sheets are taped together with an overlap along the strips ⅜ in1 cm; sheet numbers and the assembly guide are on the first page. For a copy shop or plotter, choose "One-sheet PDF".
What you get
Front and back on the fold, the sleeve and the gusset at full size, with seam allowances and a hem allowance for the elastic. The elastic lengths for the neckline and leg openings are below the drawing.
FAQ
What measurements should I take on a child?
Height, bust, waist and hip, and back waist length. You can skip the vertical torso circumference, upper arm circumference and sleeve length — the pattern maker estimates them from height using standard body measurements tables for girls. If the child is tall and slim or the opposite, it's better to take the vertical torso circumference: from the shoulder at the neck, down over the chest, between the legs and up the back to the shoulder.
What fabric should I use?
Swimwear lycra or supplex for practice and competitions, stretch velvet for a dressy swimsuit, cotton with lycra for daycare. Cut the gusset from cotton jersey. Stretch 3⅞ in10 cm of fabric across the grain: up to 4¾ in12 cm is low stretch, 12–14 is medium, more is high.
Why is the pattern smaller than the child?
A gymnastics swimsuit fits snugly: around the body it's 10% smaller than the figure at medium stretch, and 10% shorter in length. That way the swimsuit doesn't wrinkle or slip down when the child bends and jumps. Ready-made gymnastics swimsuit patterns work the same way — we checked the pattern maker against them.
How do I sew it?
Sew the shoulder seams, set the sleeves into the open armholes, then sew the swimsuit side seams and sleeve seams in one pass. Baste the gusset to the front on the wrong side and sew the inseam. Attach swimwear elastic to the neckline and leg openings with a zigzag, turn under and topstitch. Turn up the sleeve hems. Sew all seams with a serger or a stretch stitch.