What Measurement in Diameter May a Golf Ball Not Exceed?

A golf ball must not have a diameter that is less than 1.680 inches (which is 42.67 millimeters), but here's the surprising part of the answer: there is no rule specifying a maximum diameter a golf ball may not exceed. That’s right, the official Rules of Golf carefully control the minimum size but are completely silent on how big a golf ball can be. This article will explain exactly why that is, where the 1.680-inch rule came from, and walk you through the other essential golf ball specifications that the governing bodies use to ensure fairness and protect the challenge of the game.

There’s a Minimum Size, But No Maximum… Why?

You read that correctly. While you can't play a competition with a ball smaller than 1.680 inches in diameter, you could theoretically play with one the size of a tennis ball if you wanted to (though your score would suffer tremendously). The governing bodies of golf - the USGA and The R&A - don’t need to set a maximum limit because physics does it for them.

Think about it from a performance standpoint:

• Increased Drag: A larger, heavier ball would have significantly more surface area, creating much more aerodynamic drag as it flies through the air. This friction would rob the ball of speed, causing it to fly much shorter distances than its lean, 1.680-inch cousin.
• Difficulty Launching: Getting a larger sphere airborne would require more energy and a different kind of strike. For the average golfer, it would likely result in low, tumbling shots that don't travel very far.

Essentially, making a golf ball bigger offers no competitive advantage. It’s self-policing. In contrast, making a ball smaller does offer advantages, which is precisely why the minimum size rule is one of the most foundational in the equipment-rule book.

A Tale of Two Golf Balls: The History of the 1.680-Inch Rule

To understand why the minimum diameter is so important, we have to look back to a time when golf wasn't unified under one set of equipment rules. For a large part of the 20th century, there were two dominant types of golf balls.

The “American” Ball

The USGA, which governs golf in the United States and Mexico, mandated a minimum size of 1.68 inches in 1931. This larger ball was seen as more challenging and required more skill to control. It was less forgiving on mishits and forced players to be more precise.

The “British” Ball

Meanwhile, The R&A, which governs golf everywhere else in the world, allowed a smaller ball with a minimum diameter of just 1.62 inches. This smaller ball came with some significant benefits:

• More Distance: With less air resistance, the 1.62-inch ball could bore through the wind more effectively and generally flew farther.
• Easier from Trouble: On the windswept links courses of the UK, the smaller ball was a huge help. It sat down deeper in thick heather and gorse, which sounds bad, but it actually made it easier to get the leading edge of a club on the ball cleanly and "nip" it out of trouble.

This difference created a divide. Players in The Open Championship could use the smaller ball, giving them a distinct advantage over their American counterparts who were used to the larger, less forgiving version. For decades, a player’s performance could be influenced by which side of the Atlantic the tournament was being played on.

Finally, in 1990, the tide turned for good. The R&A officially outlawed the smaller ball and adopted the 1.68-inch standard, unifying the rules of golf worldwide. Since then, every conforming golf ball has had to measure at least 1.680 inches in diameter, ensuring players everywhere compete on a level playing field.

The Other Gold Ball Rules You Need to Know

The diameter is the headline act, but it’s just one piece of the puzzle. The USGA and R&A have a complete set of specifications to ensure no single ball offers an unfair "hack" or shortcut around skill. These rules work together to define what makes a golf ball "conforming."

1. Maximum Weight

Just as there’s a minimum size, there’s a maximum weight. A golf ball must not weigh more than 1.620 ounces avoirdupois (45.93 grams). Interestingly, there is no minimum weight.

The reason for this is similar to the diameter rule - physics takes care of it. A golf ball that’s too light won't have enough mass to travel far or hold its line in the wind. A ball that’s too heavy might fly farther if you could generate enough speed, but it would be much harder to launch and would get less lift. The weight limit works in tandem with the size limit to subtly control a ball's potential performance.

2. Spherical Symmetry

This is a big one. It simply states that a golf ball must be designed to be spherical and symmetrical. You aren't allowed to build an "auto-correcting" golf ball. The most famous example of a ball that broke this rule was the Polara.

In the 1970s, the Polara golf ball was introduced with a revolutionary dimple pattern - it had shallow dimples around its equator and deeper dimples at the poles. If you aligned the ball correctly on the tee, this asymmetrical design would create a 'spin axis' that dramatically reduced hooks and slices by up to 75%. You could hit a banana slice, and it would straighten out mid-air.

As you can imagine, the USGA quickly deemed it non-conforming in 1981 because it compromised the skill required to hit a straight shot. This rule ensures that your ball flies based on the quality of your swing, not based on built-in aerodynamic tricks.

3. Performance Standards (Initial Velocity and Overall Distance)

These two rules are the modern guardrails of golf ball technology. They prevent a new ball from suddenly making courses obsolete.

• Initial Velocity: When tested on a machine, the ball’s speed just after impact cannot exceed a set limit. This prevents manufacturers from making balls with an extreme "trampoline effect" that come rocketing off the clubface too fast.
• Overall Distance Standard (ODS): This is the major one. Under controlled test conditions (robot swing, specific club, etc.), the total carry and roll of a golf ball cannot exceed 317 yards (with a 3-yard tolerance). This is the primary tool the governing bodies use to cap driver distance and preserve the historical challenge of golf courses. No matter how clever a company’s aerodynamics or core technology is, the final product must not go further than this limit.

How Can You Be Sure Your Golf Ball Is Legal?

After reading all this, you might be nervously looking at the balls in your bag. Don't worry, it's pretty simple.

The USGA and The R&A maintain a publicly available "Conforming Golf Ball List" which is updated monthly. Any ball on this massive list is legal for play in any sanctioned event or for posting a handicap score.

A good rule of thumb:

If you buy new golf balls from any major, reputable manufacturer - like Titleist, Callaway, TaylorMade, Srixon, Bridgestone, a etc. - they are virtually certain to be conforming. These companies live and die by the rules and design all of their premium and standard models to pass the test.

Where you might run into trouble:

Be skeptical of balls bought from novelty shops or unknown online brands that make outrageous claims, like "guaranteed to add 30 yards" or "the anti-slice golf ball." These are often non-conforming, using technology C/like the old Polara or simply being too heavy or springy to be legal.

Using a non-conforming ball a isn't a crime, but it does mean you can't use it in a competition or for any round you intend to count toward your official handicap. It’s strictly for casual practice rounds or a friendly hit-around where rules don't matter.

Final Thoughts

So, while there’s no official maximum size a golf ball can be, physics and pragmatism make the debate moot. The crucial rule is the minimum diameter of 1.680 inches, a rule born from a desire to unify the game globally. This specification, combined with limits on weight, symmetry, and overall distance, creates the framework that challenges our skill and keeps the game we love fair for everyone.

Understanding these equipment subtleties is part of playing smarter, more confident golf. Of course, you can't be expected to be an expert on every rule out there. That is where I feel our product can serve golfers like yourself a lot better a. If you ever find yourself in a tricky situation on the course, whether it’s a question about a ball being in or out of bounds, what an unplayable lie means, or how to take a proper drop, I invite you to ask Caddie AI. AIt gives you a 24/7 rules official a in your pocket a, providing instant, clear answers Aso that you you can make the right call,, feeling confident in your decision.