A regulation golf cup is exactly 4.25 inches (108 mm) in diameter. This measurement is standardized worldwide by both the USGA and the R&A, the two governing bodies of golf, and applies to every course from your local municipal links to the Masters at Augusta National.
Why 4.25 Inches?
The size traces back to a surprisingly practical origin. In 1829, greenkeepers at Musselburgh Links in Scotland invented the first known hole-cutter, a tool that happened to cut a circle 4.25 inches across. For decades, hole sizes varied from course to course, but in 1891 the Royal and Ancient Golf Club of St. Andrews decided to standardize. They liked the Musselburgh cutter’s dimensions and wrote 4.25 inches into the official rules. The exact reason the original tool was built to that size is lost to history.
That original hole-cutter still exists and is on display in the clubhouse at Royal Musselburgh.
Depth and Liner Requirements
The rules specify more than just width. A golf hole must be at least 4 inches (101.6 mm) deep. Most courses use a plastic or metal liner inside the hole to keep its shape intact. If a liner is used, its outer diameter cannot exceed 4.25 inches, and it must sit at least 1 inch below the putting green surface. The only exception is when soil conditions physically prevent sinking the liner that deep.
These dimensions matter because the relationship between cup width and ball size is what makes putting so precise. A standard golf ball is 1.68 inches in diameter, meaning the hole is roughly 2.5 times wider than the ball. That sounds generous, but factor in the speed, break, and grain of a putting green and the margin for error shrinks fast.
How the Hole Is Cut and Maintained
Course maintenance crews reposition the hole on each green regularly, often daily at busy courses and during tournaments. A modern hole-cutter works like a cylindrical punch: it’s pressed straight down into the green to produce a clean, vertical plug of turf and soil. The cut needs to be perfectly round and perpendicular to the surface. A tilted or ragged hole can cause the edges to collapse, which is why groundskeepers pay close attention to soil moisture and firmness when choosing where to place the pin.
Hole placement also rotates around the green to distribute foot traffic evenly. Constant wear around one spot compacts the turf and causes the rim to break down, making putts bounce unpredictably off damaged edges.
Bigger Cups for Beginners
Some programs and charity events use oversized holes to make the game more accessible. The most common alternative is a 15-inch cup, more than three times the regulation diameter. The concept gained attention through events hosted by Golf Digest and later promoted by the Southern California Golf Association, where full 18-hole rounds were played with the larger cups.
The idea isn’t to replace the standard hole but to create what advocates call a “bunny slope” for newcomers. Sinking putts more often keeps beginners engaged and reduces the frustration that drives many people away from the game early on. Other experimental sizes have included 8-inch and 12-inch cups, though none of these are recognized in official play. For sanctioned rounds, competitive events, and posted scores, 4.25 inches remains the only legal size.