Quick answer

To find your MyONE custom fit size, measure your erect girth with a flexible tape at the widest point, then measure erect length from base to tip. Match your girth to a two-digit Girth Number and your length to a letter (e.g., 64L, 55G, 57K). Order a few sizes near your measurements to confirm comfort before committing.

Why standard condoms often miss the mark

Most condoms sold in stores come in a narrow range of nominal widths, typically 52–56mm, with a single length. If your girth falls outside that range, you may experience slippage, tightness, or reduced sensation. MyONE uses a FitCode system that separates girth and length, so you can dial in both dimensions independently. This matters because a condom that is too tight can be uncomfortable and more likely to break, while one that is too loose can slip off. The goal is a snug, secure fit that stays put without pinching.

Measure girth accurately

Use a flexible measuring tape or a piece of string that you later measure against a ruler. Wrap it around the widest part of your erect penis, usually near the base or mid-shaft. Keep the tape snug but not compressing the skin. Record the measurement in millimeters or inches. This number is the most important factor for condom fit because nominal width is based on circumference. If you measure in inches, multiply by 25.4 to get millimeters. For example, a 5.5-inch girth equals about 140mm circumference, which corresponds to a nominal width around 64mm.

Measure length from base to tip

Measure along the top of your erect penis from the pubic bone to the tip. Do not include the foreskin if uncircumcised; measure to the tip of the glans. Use a ruler pressed gently against the pubic bone for consistency. Length determines the letter in MyONE's FitCode. For instance, 8.5 inches corresponds to L, 8 inches to E, and 6.5 inches to G. If your length falls between letters, choose the smaller letter if you want a snugger fit at the base, or the larger letter if you prefer more coverage.

Match your measurements to a FitCode

MyONE FitCodes combine a two-digit Girth Number and a length letter. The Girth Number is the nominal width in millimeters (e.g., 55, 57, 64). The letter indicates length range. For example, 64L is for a 64mm nominal width and 8.5-inch length; 55G is 55mm width and 6.5-inch length; 57K is 57mm width and 8-inch length. If your girth is between two numbers, choose the smaller number for a tighter fit or the larger for a looser fit. If your length is between two letters, consider how you prefer the condom to sit—some users prefer a little extra length for comfort, others prefer a snug base.

Test your fit before you commit

Order a few condoms in sizes around your measurements—one at your calculated FitCode, one slightly smaller girth, and one slightly larger. Try them during masturbation or with a partner to see how they feel. A good fit should roll down smoothly, stay in place during movement, and feel comfortable without leaving deep marks. If the condom bunches at the base or slides, adjust your girth number. If it feels too tight or leaves red indentations, go up a girth number. Remember that MyONE condoms are triple tested for safety and made from hyperthin, extra lubricated vegan latex, so the material itself is consistent across sizes.

Step-by-step sizing checklist

  1. Measure girth at the widest point: Wrap a flexible tape around your erect penis, keeping it snug but not tight. Record the circumference in millimeters. Common mistake: measuring flaccid or pulling the tape too tight. Always measure erect and relaxed.
  2. Measure length from pubic bone to tip: Press a ruler gently against the pubic bone and measure along the top to the tip of the glans. Checkpoint: do not add extra length for the reservoir tip; measure only to the tip.
  3. Convert girth to nominal width: Divide your girth measurement by 3.14 (pi) to get the diameter, which is close to the nominal width. For example, 180mm girth ÷ 3.14 ≈ 57mm. Mistake to avoid: using circumference directly as nominal width; the numbers are different.
  4. Match to a FitCode: Find the Girth Number closest to your nominal width and the Length Letter closest to your length. Use the MyONE size chart to see available combinations. If between sizes, order both and test.
  5. Order a test pack: Buy one condom in your calculated size and one size up or down in girth. Try them on to see which feels more secure and comfortable. A good fit stays put during movement and leaves no deep marks.
  6. Adjust as needed: If the condom slips, reduce the girth number. If it feels too tight or leaves red rings, increase the girth number. For length, a shorter letter gives a snugger base; a longer letter gives more coverage. Re-measure occasionally; bodies can change.

MyONE sizes to know

  • MyONE® Size 64L My Custom Fit® Condom: MyONE® Size 64L My Custom Fit® Condom combines Girth Number 64 (64mm nominal width) with Length Letter L (8.5 inches). If your girth is around 64mm and length around 8.5 inches, this is your starting point. It is one of the widest and longest options in the MyONE range.
  • MyONE® Size 55G My Custom Fit® Condom: MyONE® Size 55G My Custom Fit® Condom combines Girth Number 55 (55mm nominal width) with Length Letter G (6.5 inches). This size suits those who need a little more girth than standard but a shorter length. It is a good match if your measurements are near 55mm girth and 6.5 inches length.
  • MyONE® Size 57K My Custom Fit® Condom: MyONE® Size 57K My Custom Fit® Condom combines Girth Number 57 (57mm nominal width) with Length Letter E (8 inches). Ideal if you need a slightly wider and longer fit than standard. Use this if your girth is around 57mm and length around 8 inches.