ED ring size chart
ED ring size chart: will a FirmTech ring fit you?
Last updated: November 3, 2026Published by FirmTech
Every FirmTech ring comes in one size that fits up to 5.5 inches (14 cm) of erect girth, which FirmTech says covers 95% of men.
There is no small, medium or large to choose. The TechRing, Performance Ring and MaxPR all use an adjustable hook-and-loop strap, so the same ring sets to your exact size. What does change between rings is tightness: the MaxPR sits snuggest.
This guide is published by FirmTech, which makes every ring it covers. It is not independent. Ratings and quotes come from FirmTech’s own reviews and product pages, as of November 2026.
What size erection ring do I need?
If your erect girth at the base is 5.5 inches (14 cm) or less, any FirmTech ring fits. Measure once with a soft tape or a piece of string, then check the chart below or use the fit checker.
| Erect girth (inches) | Erect girth (cm) | FirmTech fit |
|---|---|---|
| 4.0 in | 10.2 cm | Within range |
| 4.5 in | 11.4 cm | Within range |
| 5.0 in | 12.7 cm | Within range |
| 5.5 in | 14.0 cm | Within range, the published maximum |
| Over 5.5 in | Over 14 cm | Outside the published range; ask FirmTech first |
Check your fit
Assumption: FirmTech’s published limit of 5.5 inches (14 cm) erect girth for all three rings. This is an estimate, not a medical or fitting decision.
How to measure for an erection ring
Wait until erect. Girth changes a lot, so measure when fully erect.
Wrap the base. Wrap a soft tape measure or a piece of string around the base of the penis.
Read the length. If you used string, mark it and measure it against a ruler.
Compare. At 5.5 inches (14 cm) or less, FirmTech rings fit.
Tightness by ring
Size is the same for all three, but the feel is not. The Performance Ring is FirmTech’s comfort fit at 3 of 5, comfort, with up to 12 hours of wear. The TechRing is rated 3 of 5, secure, also for up to 12 hours. The MaxPR is the tightest at 5 of 5, tightest, so its wear limit is 90 minutes.
To put any of them on: hold the loop open, drop the testicles through it, set the second loop around the base of the penis, then adjust for comfort. It is designed to go on while you are soft. If you are not sure about fit, the TechRing’s 30-day risk-free trial covers you, and FirmTech offers a 30-day money-back guarantee on its products.
Next, read about erection ring side effects and safe wear times, compare all three in the FirmTech ring comparison, or go back to the performance ring reviews overview.
Common questions
- Is there an ED ring size chart for FirmTech rings?
- FirmTech rings come in one size, so there is no multi-size chart. All three rings fit up to 5.5 inches (14 cm) of erect girth, and FirmTech says one size fits 95% of men. The adjustable strap sets the tension. This site’s size chart page includes a quick checker that compares your measurement with that limit. See this 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, then measure the string against a ruler. If the result is 5.5 inches (14 cm) or less, FirmTech’s rings fit. If you are unsure, the TechRing’s 30-day risk-free trial covers you while you find out. See this in the full FAQ
- What if my girth is over 5.5 inches?
- FirmTech lists 5.5 inches (14 cm) of erect girth as the maximum fit for all three rings, so a larger measurement is outside the published range. Rather than forcing a fit, ask FirmTech through its contact page before you buy. A ring that is too tight is uncomfortable and works against the point of an adjustable design. See this in the full FAQ
- Which FirmTech ring is the tightest?
- The MaxPR is the tightest. FirmTech rates its tightness 5 of 5 and describes it as slimmer and snugger than the Performance Ring, for maximum hardness and more intense orgasms. Because of that extra pressure, its safe wear time is up to 90 minutes, compared with up to 12 hours for the Performance Ring and the TechRing. See this in the full FAQ
- Can I put the ring on before I have an erection?
- Yes. FirmTech’s rings are designed to go on when you are soft, so you can put one on discreetly ahead of time. Loop it behind the testicles and around the base of the penis, then adjust the hook-and-loop strap so it is snug but not tight. FirmTech says the whole process takes a few seconds. See this in the full FAQ
- Are FirmTech rings comfortable?
- FirmTech makes its rings from soft, medical-grade, latex-free elastomer with an adjustable hook-and-loop fit and nothing hard or rigid. It rates the Performance Ring as its comfort fit. Verified reviewer Dave, 47, called it “Simple, comfortable, and it just works.” One TechRing reviewer noted that overnight wear took some getting used to. See this in the full FAQ