What size ED ring do I need?
If your erect girth at the base is 5.5 inches (14 cm) or less, the one-size Performance Ring and MaxPR are listed to fit you, and the adjustable strap handles the rest.
Fixed rings make you choose an inside diameter, and a wrong guess can mean a ring that is loose or too tight. FirmTech's hook-and-latch design avoids that guesswork: you set the tension on the body. FirmTech says the same one size fits 95% of men on its TechRing page; the Performance Ring and MaxPR share the 5.5 inch listed fit.
ED ring size chart in inches and centimeters
| Erect girth (in) | Erect girth (cm) | Performance Ring and MaxPR |
|---|---|---|
| 4.0 in | 10.2 cm | Within listed fit |
| 4.5 in | 11.4 cm | Within listed fit |
| 5.0 in | 12.7 cm | Within listed fit |
| 5.5 in | 14.0 cm | Within listed fit (maximum) |
| 6.0 in | 15.2 cm | Above listed fit: contact FirmTech |
| 6.5 in | 16.5 cm | Above listed fit: contact FirmTech |
How do I measure for an erection ring?
Wait until erect
Girth changes a lot between soft and erect, so measure when erect.
Wrap at the base
Wrap a soft tape measure, or a piece of string, around the base of the penis where the ring sits.
Read the number
Read the tape, or mark the string and measure it against a ruler.
Compare
At 5.5 inches (14 cm) or less you are within the listed fit. Use the checker below to confirm.
Check your fit
Fit checker
Enter your erect girth measured around the base. Checks against FirmTech's listed fit of up to 5.5 in (14 cm).
Tightness differs by ring, not size
Within the same fit range, the Performance Ring is rated 3 of 5 for tightness and the MaxPR 5 of 5. If you are near the top of the range or new to rings, the Performance Ring is the gentler start. If you are outside the range, please contact FirmTech. Back to the ED ring for men guide.
Common questions
- What size ED ring do I need?
- FirmTech rings are one size with adjustable tension and fit up to 5.5 inches (14 cm) of erect girth measured at the base, so there is no size to pick. Measure with a soft tape or string around the base when erect. At 5.5 inches or less, the Performance Ring and MaxPR fall within the listed fit. In the full FAQ
- How do I measure for an erection ring?
- When erect, wrap a soft tape measure or a piece of string around the base of the penis. Mark where it meets, then measure the string with a ruler. Compare the number to the listed fit of up to 5.5 inches, which is 14 cm. The fit checker on our size chart page does the comparison for you. In the full FAQ
- What if my girth is over 5.5 inches?
- Then you are outside the fit FirmTech lists for its rings, so ask FirmTech before buying. Contact the company through its contact page with your measurement. A ring that is too tight can be uncomfortable or unsafe, so do not force a fit beyond the listed range. In the full FAQ
- Can I adjust how tight the ring is?
- Yes. Both the Performance Ring and the MaxPR use a hook-and-latch design with adjustable tension, so you control how snug it feels. The MaxPR is built slimmer and tighter overall, so expect it to feel snugger than the Performance Ring. Aim for snug, never painful. In the full FAQ
- Is there an ED ring size chart for FirmTech rings?
- Yes, and it is short because the rings are one size. All three FirmTech rings list a fit up to 5.5 inches (14 cm) of erect girth with adjustable tension. Our size chart page shows that range in inches and centimeters and explains how tightness differs between the Performance Ring and the MaxPR. In the full FAQ