Enter your driver swing speed. Get the shaft flex range that matches — plus the reasons most golfers get this wrong.
Don't have a number? Most launch monitors show clubhead speed. A typical male amateur is 85-95 mph.
Every time you swing a driver, the shaft bends, loads energy, and then unloads that energy into the ball at impact. How much it bends depends on two things: the shaft's built-in stiffness, and how hard you swing. If those two aren't matched, the shaft either doesn't bend enough (too stiff — low launch, weak contact, loss of distance) or bends too much (too soft — timing becomes unpredictable, face angle wanders, directional misses get worse).
The standard industry lookup table below has been around for decades. It's a reasonable starting point because clubhead speed is the single biggest driver of which flex you need. But it's only part of the picture.
| Driver swing speed (mph) | Flex |
|---|---|
| Under 65 | Ladies (L) |
| 65–74 | Senior (A) |
| 75–84 | Regular (R) |
| 85–94 | Regular / Stiff (R/S) |
| 95–104 | Stiff (S) |
| 105–114 | Extra Stiff (X) |
| 115 and above | Tour X / XX |
Brand variance is real. A True Temper Dynamic Gold S300 plays firmer than a KBS Tour Stiff. A Fujikura Ventus Stiff plays firmer than a Mitsubishi Tensei Stiff. There's no ISO standard for shaft flex — every manufacturer has their own deflection spec, so the same label tells you different things from different companies.
Tempo matters as much as speed. A 95-mph swinger with a quick transition needs a stiffer profile than a 95-mph swinger with a smooth, gradual tempo. The table above treats all 95-mph players the same — they're not.
Weight interacts with flex. Two shafts with the same "Stiff" label but 20 grams of weight difference will feel and perform completely differently. Weight often matters more than the flex letter. We built a separate tool for swing speed to shaft weight — run that next.
Your typical miss changes the recommendation. A 95-mph player who fades the ball and a 95-mph player who hooks the ball may need different shafts, even at the same speed, because the shaft's torque and tip stiffness affect face angle at impact differently for each swing shape.
This isn't a fitting — it's a starting point you can trust. Walk into a fitter already knowing your flex band, and the real work of picking a shaft gets a lot faster.
Want the same kind of read on all 14 clubs in your bag? Grade My Bag is free and takes about 3 minutes. Or drill into one specific club with launch monitor data using the Single-Club Fit Grader.
Shaft flex is how much a golf shaft bends during your swing. Too stiff and the ball launches low with weak contact. Too soft and the shaft whips unpredictably, causing inconsistent flight. The right flex matches your swing speed so the shaft loads and unloads at the right moment.
Most driving ranges now have launch monitors that display clubhead speed. You can also use at-home radar devices like the Garmin R10 or Swing Caddie. If you don't know, use our distance estimate — a 230-yard carry driver typically means ~95 mph clubhead speed.
There's no industry standard. A Stiff from one brand can play like a Regular from another. Weight, torque, and kickpoint all affect how a shaft actually feels at your swing speed. Use the flex label as a starting point, not a final answer.
No. This is a starting point. A professional fitting uses launch monitor data, dynamic lie board readings, and trial-and-error across multiple shafts. What this tool gives you is a defensible baseline — if you walk into a fitting already knowing you're in the Stiff band, you can skip the guesswork.
It doesn't tell you about weight, kickpoint, torque, or brand-specific behavior. It doesn't factor in your tempo, transition, or typical miss — those matter just as much as speed. Our free AI analysis layers those in. For full bag analysis across 14 clubs and 6 fit dimensions, use Grade My Bag.
Get a full grade for your whole bag — free, takes about 3 minutes.
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