Maru Swimwear Size & Fit Guide

Use this guide to find the right Maru swimwear size. Measure first using the steps below, then compare your measurements with the size chart for your range.

Women’s & girls’ sizes

How to measure

Diagram of a woman and a girl in one-piece swimsuits showing where to measure: 1 chest, 2 waist, 3 hips and 4 body loop.

Use a soft tape measure and measure over underwear or swimwear, not clothes. Stand straight and relaxed with arms by your sides. Keep the tape snug but not tight, level all the way round, and breathe normally. It’s easier and more accurate if someone helps – and best if you measure children for them.

  1. Chest: measure around the fullest part of the chest, with the tape under the arms and across the shoulder blades at the back.
  2. Waist: measure around the natural waistline – the narrowest part of the torso, usually just above the belly button.
  3. Hips: with feet together, measure around the fullest part of the hips.
  4. Body loop: start at the top of one shoulder, where the strap would sit. Run the tape down the front of the body, between the legs and back up the back to the same point. This tells you whether a one-piece will be long enough in the body.

Between sizes? Take a look at our Tie Back styles, available for women and girls. The adjustable tie straps let you set how snug the suit sits and how much support you get. For girls, we recommend choosing the larger size to give them room to grow.

Women’s size chart
Women’s size chart
Maru size 28 30 32 34 36 38
International sizes
UK 28 30 32 34 36 38
DE 32 34 36 38 40 42
FR 32 34 36 38 40 42
IT 38 40 42 44 46 48
Body measurements (cm)
Chest 73.7–78.7 78.7–83.8 83.8–88.9 88.9–94 94–99.1 99.1–104
Waist 53.3–58.4 58.4–63.5 63.5–68.6 68.6–73.7 73.7–78.7 78.7–83.8
Hips 78.7–83.8 83.8–88.9 88.9–94 94–99.1 99.1–104 104–109
Body loop 142–147 147–152 152–157 157–163 163–168 168–173
Body measurements (inches)
Chest 29–31 31–33 33–35 35–37 37–39 39–41
Waist 21–23 23–25 25–27 27–29 29–31 31–33
Hips 31–33 33–35 35–37 37–39 39–41 41–43
Body loop 56–58 58–60 60–62 62–64 64–66 66–68
Girls’ size chart
Girls’ size chart
Maru size 5–6 yrs 7–8 yrs 9–10 yrs 11–12 yrs 13–14 yrs
International sizes
UK 24 26 28 30 32
DE 116 128 140 152 164
FR 5–6 ans 7–8 ans 9–10 ans 11–12 ans 13–14 ans
IT 5–6 anni 7–8 anni 9–10 anni 11–12 anni 13–14 anni
Body measurements (cm)
Chest 61–66 66–73.7 73.7–78.7 78.7–83.8 83.8–88.9
Waist 53.3–58.4 58.4–61 61–63.5 63.5–66 66–68.6
Hips 68.6–73.7 73.7–78.7 78.7–83.8 83.8–88.9 88.9–94
Body loop 132–137 137–142 142–147 147–152 152–157
Body measurements (inches)
Chest 24–26 26–29 29–31 31–33 33–35
Waist 21–23 23–24 24–25 25–26 26–27
Hips 27–29 29–31 31–33 33–35 35–37
Body loop 52–54 54–56 56–58 58–60 60–62

Men’s & boys’ sizes

How to measure

Diagram of a man and a boy in jammers showing where to measure: 1 waist and 2 hips.

Use a soft tape measure and measure over underwear or swimwear, not clothes. Stand straight and relaxed with arms by your sides. Keep the tape snug but not tight, level all the way round, and breathe normally. It’s easier and more accurate if someone helps – and best if you measure children for them.

  1. Waist: measure around the natural waistline, roughly level with the belly button. Don’t pull the stomach in.
  2. Hips: with feet together, measure around the fullest part of the hips.

Between sizes? For boys who are between sizes, we recommend choosing the larger size to give them room to grow.

Adjustable fit: all our jammers come with an adjustable waist cord, so you can tighten or loosen the waist for the perfect fit.

Men’s size chart
Men’s size chart
Maru size 28 30 32 34 36 38
International sizes
UK 28" 30" 32" 34" 36" 38"
DE 2 3 4 5 6 7
FR 71 76 81 86 91 96
IT 42 44 46 48 50 52
Body measurements (cm)
Waist 68.6–73.7 73.7–78.7 78.7–83.8 83.8–88.9 88.9–94 94–99.1
Hips 73.7–78.7 78.7–83.8 83.8–88.9 88.9–94 94–99.1 99.1–104
Body measurements (inches)
Waist 27–29 29–31 31–33 33–35 35–37 37–39
Hips 29–31 31–33 33–35 35–37 37–39 39–41
Boys’ size chart
Boys’ size chart
Maru size 5–6 yrs 7–8 yrs 9–10 yrs 11–12 yrs 13–14 yrs
International sizes
UK 22 24 26 28 30
DE 104 116 128 140 152
FR 5–6 ans 7–8 ans 9–10 ans 11–12 ans 13–14 ans
IT 5–6 anni 7–8 anni 9–10 anni 11–12 anni 13–14 anni
Body measurements (cm)
Waist 55.9 58.4–63.5 63.5–68.6 68.6–73.7 73.7–78.7
Hips 58.4–63.5 63.5–68.6 68.6–73.7 73.7–78.7 78.7–83.8
Body measurements (inches)
Waist 22 23–25 25–27 27–29 29–31
Hips 23–25 25–27 27–29 29–31 31–33

Check the fit

Try your new swimwear on over underwear and check it against the points below. Training suits are meant to feel snug when dry – the fabric gives a little once it’s wet – so the real question is whether it stays put while you move.

Swimsuits

Good fit

  • Lies flat against the body, with no baggy fabric at the chest, back or seat.
  • Straps sit on the shoulders without slipping off or digging in.
  • Leg openings sit smoothly without cutting in or gaping.
  • You can swing your arms through a full stroke without the suit pulling at the shoulders.

Try a size up

  • Straps dig in or leave deep marks.
  • The suit pulls down on your shoulders when you bend – usually a sign the body loop is too short.
  • Leg openings dig in or leave red marks.

Try a size down

  • Fabric wrinkles or bags at the chest, back or seat.
  • Straps keep slipping off your shoulders.
  • Water fills the suit when you push off the wall.
Jammers

Good fit

  • The waistband sits flat once the cord is tied, without rolling.
  • Legs stay in place above the knee and don’t ride up when you kick.
  • You can squat comfortably without the jammers pulling down at the back.

Try a size up

  • The waistband or leg hems leave deep marks.
  • The jammers pull down at the back when you squat.

Try a size down

  • The jammers still slip down with the waist cord tied.
  • Fabric bags at the seat or the legs ride up.