Baseballs – key facts about dimensions, composition, and other properties
The popularity of baseball in the United States and around the world is matched only by a few other sports. This sport is easy to learn and invites participation at all levels while providing prime time entertainment for the masses. Millions of kids grow up pitching and hitting baseballs while dreaming about a big league career and the money and fame that come with it. At the center of this dream is a small bouncy ball that any child can easily hold in one hand, and it’s worth considering its design and dimensions to better understand what makes it unique. Since an average person doesn’t know how much does a baseball weigh and what materials it’s made of, we will try to present key facts about baseballs and put them in proper context.
A short history of a baseball design
The roots of the sport of baseball stretch back into the 19th century, and at first, a wide variety of balls was used in play. It was recognized early on that standardizing baseball’s size, and weight would bring about more balanced competition. Already in this era, balls were typically made from rubber, yarn, and leather, with their properties depending on the exact materials used and the amount of rubber added.
In 1876, the emergent National League chose Spalding as its exclusive manufacturer of baseballs and maintained this relationship for full 100 years. Those balls initially contained wooden cores wrapped with other materials. A big innovation was introduced in 1910 when the cork core was invented, soon to be improved into a ‘cushion core’ by adding a layer of rubber around the cork. In 1934, American League and National League agreed on standard baseballs to be used in all games – that looked mostly like modern balls. With only a few minor changes in design and production procedures, what a baseball is made of remained mostly the same throughout the 20th and early 21st centuries.
Specifications of a modern baseball

How much does a baseball weigh?
If you have ever wondered how heavy a baseball is, the answer is it must weigh between 5 and 5 ¼ ounces (142-149 grams) to be considered legal in most competitions, including MLB. Its circumference has to stay within the 9 – 9 ¼ inches range (between 22.9 and 23.5 cm), while its diameter needs to measure approximately 3 inches (7.6 cm). While those are the regulation sizes for balls used in professional baseball, there are both lighter and heavier balls that may be occasionally used in some competitions (i.e., Little League baseball uses balls that are under 5 ounces).
Composition of a baseball
Regarding the composition of a baseball, it includes several separate layers that are compacted together. At the center of the ball is the core that can be made of cork, rubber, or a combination of the two. The next layer consists of yarn wrapping that is tightly packed around the core. Finally, the ball’s surface is covered by cowhide, which is stitched together with a total of 108 double stitches arranged in a recognizable 8-figure pattern. The stitching gives the baseball its distinctive look and impacts how the ball moves through the air, which is the reason the pattern must be standardized.
Notably, despite all the technological advances, baseballs are still manufactured by hand as the process can’t be automated without negatively affecting quality. There is also a distinction between baseballs intended for professional use, which are very hard and need to be tempered before use and recreational baseballs that require no such preparation.
How ball properties affect baseball performance
It’s not hard to fathom that what a baseball is made of and how it has been stitched affects how it will behave while in play. Since baseball is a sport where precision is extremely important, even slight differences in the physical properties of the ball can cause different outcomes. Lighter and bouncier balls are more likely to travel far when hit, facilitating more home runs and points scored. This explains why modern offensive statistics differ so greatly from the early 20th century when a much heavier and more inert, so-called ‘dead ball’ was used that favored the defensive side.
In addition to how much does a baseball weigh, the structure of its surface can significantly impact play, in particular pitching. Pitchers need to have a strong grip on the ball in order to control its trajectory, leading to the illegal but frequent practice of applying various sticky substances (i.e., pine tar) to the ball before throwing. It’s important to draw a distinction between such attempts at cheating by individual players and the application of rubbing mud under the supervision of the officials, which is done to soften the surface of the hide.
Who makes baseballs for MLB?
Like most other professional sports leagues, Major League Baseball has an exclusive supplier of balls that delivers all of the game-used baseballs. This supplier is Rawlings, a Missouri-based company that also produces other baseball equipment such as gloves and bats. Rawlings supplanted Spalding as the official baseball manufacturer for MLP in 1976 and remained in this role without interruption to this day.
Having the same supplier and the same ball design for several decades has certainly helped the modern generation of players develop a comfort zone that would be difficult to attain if they had to adjust to frequent changes.
Where are MLB baseballs made?
In case you are wondering where MLB baseballs are made, you might be surprised they are actually imported. Rawlings operates a plant in Costa Rica, where all balls used in professional baseball are hand-made by local workers. However, the raw materials are hauled from the United States, and the quality of finished baseballs is strictly controlled. In general, baseballs are manufactured 6-12 months before they are used and distributed to all the teams. Since new baseballs are introduced at the start of each half-inning and warm up balls are usually given to fans, and having a large stockpile of game-approved balls is imperative for every MLB team.