Sizing
How to Measure for an ED Ring
Published by FirmTech · Last updated
Measure erect girth around the base of the penis with a soft tape or string; at 5.5 inches (14 cm) or less, every FirmTech ring fits.
In the FirmTech Ring Fit Guide, measuring is the only sizing step, because the TechRing, Performance Ring and MaxPR are one adjustable size. Take one reading at the base while erect, compare it with 5.5 inches, and use the checker below if you measured in centimeters.
How do I measure for an erection ring?
Wrap a soft tape around the base of the erect penis and read the number where it meets. This is the same method FirmTech gives on its own fit guidance.
Get a soft tape or string
A flexible sewing tape is best. A metal tape measure will not wrap properly.
Measure when fully erect
A soft measurement understates your size. The ring has to fit at full erection.
Wrap at the base
The ring sits at the base, so that is where girth matters. Keep the tape flat and snug.
Read and compare
With string, mark the overlap and lay it on a ruler. Compare with 5.5 inches (14 cm).
New here? Start with the ED ring size chart and ring chooser, then come back to this page.
Check your number
Type your measurement and pick inches or centimeters. The checker only compares your number with the fit range FirmTech states; it does not store anything.
FirmTech fit checker
Enter your erect girth measured around the base. Nothing you type leaves this page.
Assumptions: fit limit of 5.5 in (14 cm) erect girth as stated by FirmTech; 1 in = 2.54 cm. This is an estimate of fit, not a medical assessment.
Common measuring mistakes
Four mistakes that give a wrong reading
Measuring length instead of girth. Ring fit depends on circumference, not length. Measuring along the shaft. The shaft can be wider or narrower than the base, and the ring sits at the base. Pulling the tape tight. Squeezing reads small; keep it flat and snug. Measuring soft. FirmTech rings go on while soft, but the 5.5 inch limit refers to erect girth. If you get two different readings, use the larger one and compare it with the chart. Because the strap adjusts, a reading that is a little under the limit is fine; you tighten the strap until the ring is snug, never painful.
Inches to centimeters for ring sizing
| Inches | Centimeters | FirmTech fit |
|---|---|---|
| 4.00 in | 10.2 cm | Within range |
| 4.25 in | 10.8 cm | Within range |
| 4.50 in | 11.4 cm | Within range |
| 4.75 in | 12.1 cm | Within range |
| 5.00 in | 12.7 cm | Within range |
| 5.25 in | 13.3 cm | Within range |
| 5.50 in | 14.0 cm | Within range |
| 5.75 in | 14.6 cm | Above stated range |
| 6.00 in | 15.2 cm | Above stated range |
What to do after you measure
Within range? Choose by use, not size. The best tension rings for ED guide compares the three FirmTech rings on the same criteria, and the how to wear page shows how to set the strap. Above range? Contact FirmTech before ordering so they can answer for your measurement.
Measured 5.5 inches or less?
Every FirmTech ring fits. Free discreet shipping over $100 and a 30-day money-back guarantee.
Measuring questions
How do I measure for an erection ring?
Measure erect girth around the base of the penis with a soft tape measure or a piece of string, then lay the string against a ruler. If the number is 5.5 inches (14 cm) or less, the TechRing, Performance Ring and MaxPR all fit. The fit checker on the How to measure page checks your number for you. More in the FAQ
What size ED ring do I need?
With FirmTech you need only one size, because every FirmTech ring is a single adjustable size that fits up to 5.5 inches (14 cm) of erect girth. FirmTech says this one size fits 95% of men. The hook-and-loop strap tightens to your exact size, so there is no numbered size to pick. More in the FAQ
What if my girth is more than 5.5 inches?
A measurement above 5.5 inches (14 cm) is outside the fit range FirmTech states for its rings. FirmTech backs every order with a 30-day money-back guarantee, so a ring that does not fit can be returned. For a specific answer about your measurement before you buy, contact FirmTech customer service. More in the FAQ
Should an ED ring be tight?
An ED ring should feel snug but not tight. FirmTech tells wearers to fasten the strap snug, then fine-tune for comfort. Pressure should be firm enough to hold blood in and never painful. If you feel pain, numbness or coldness, loosen or remove the ring, which is good practice with any constriction ring. More in the FAQ
Can I put the ring on before I have an erection?
Yes. FirmTech rings are designed to go on when you are soft, so you can put one on discreetly ahead of time. The hook-and-loop strap lets you adjust the tension once it is in place, and there is nothing to take beforehand and no planning ahead. More in the FAQ