“Flex” refers to the ability of a golf shaft to bend during the golf swing.
Unfortunately there is no official standard measurement of the flex / stiffness of a shaft. Some producers use their own codes (like Miyazaki’s International Flex Code), but many manufacturers use popular stiffness scale, with grades expressed as a single letter:
- L (Ladies) – the most flexible, designed for women or high handicapers
- A or M (Amateur, Moderate, Mature) – designed for seniors or mid-high handicapers
- R (Regular) – designed for average male player, mid handicapers
- S or F (Stiff, Firm) – designed for low handicapers
- X or T (eXtra stiff, Tour) – designed for scratch or professional players
The flex indication is usually printed on the shaft.
The lack of one universal standard means that two models designated as Regular by two manufacturers may differ from each other. The one company’s Regular may be more like the Stiff than the Regular of another company.
Sometimes, for marketing reasons, a “slight overstiffing” can be observed in the marking of the shafts. Simply speaking the “Stiff” shaft sounds better for some golfers’ ego than the “Regular” one, although the actual flex of both shafts is similar.
Nevertheless many shaft manufactures publish their own tables that determine the appropriate shaft flex / stiffness for a given golfer. The result usually depends on the total shot distance or swing speed. The calculator below use averaged values and estimates the recommended flex.
Naturally, this method may not be perfect for all golfers, but it helps in the initial selection of the proper shaft. Please remember about the most important factor in the calculation and enter the AVERAGE, NOT THE HIGHEST shot lengths or swing speed.
update: February 2022