WNBA Ball Size: Exact Weight, PSI and NBA Difference

A WNBA basketball is size 6. The familiar product label is 28.5 inches in circumference and 20 ounces, compared with the NBA’s size 7 ball at 29.5 inches and 22 ounces.

That shorthand is useful, but the official rule is slightly broader. The 2026 WNBA rule book permits a circumference from 28.5 to 29 inches, a weight from 18 to 20 ounces and pressure of 7 psi. The NBA and WNBA game balls also use different cover materials. Size is the headline difference, not the only one.

WNBA ball size vs NBA at a glance

Using the common labels, the WNBA ball is one inch smaller around and two ounces lighter. That is a comparison of standard size 6 and size 7 products, not a claim that every approved ball sits at the exact midpoint of a league’s permitted range.

Why 28.5 inches and 20 ounces are not the whole rule

Search results and store listings usually give one neat pair of numbers: 28.5 inches and 20 ounces. Those are the standard commercial measurements Wilson uses for size 6. They are the right numbers to look for when buying a regulation-size women’s basketball.

The WNBA rule book must cover game equipment rather than store labels, so it provides tolerances. Rule 1 allows an approved WNBA ball between 28.5 and 29 inches around and between 18 and 20 ounces. It also sets the ball at 7 psi.

This distinction explains why two credible pages may show slightly different figures without one necessarily being wrong. One may be describing the product category; the other may be quoting the legal range used for equipment inspection.

The balls differ in material and pressure too

The old shortcut that the WNBA and NBA balls are identical except for size is inaccurate.

The WNBA introduced its current Wilson game ball for the 2021 season. The league describes it as a 100% composite-leather ball built on Wilson’s Evo NXT construction, with laid-in channels and a textured cover intended to manage moisture and grip.

Wilson’s NBA game ball uses genuine Horween leather. It can feel slick and firm when new, then gains grip as the leather breaks in. The WNBA composite cover is designed to deliver its playing feel without that same leather break-in process.

Inflation differs as well. The WNBA rule book says 7 psi; NBA rules recommend 7.5 to 8.5 psi. Pressure affects bounce and feel, so a player comparing the balls may be noticing more than the one-inch circumference gap.

Why does the WNBA use a smaller ball?

Size 6 is intended for smaller average hand spans. Reducing the circumference changes how far the fingers must spread around the ball and can make gripping, passing and controlling it more comfortable. Wilson uses the same hand-span reasoning in its sizing guidance.

That does not mean every woman prefers size 6 or every man needs size 7. Players in public basketball discussions describe mixed experiences. Some find the smaller ball easier to control. Others who learned with size 7 say the lighter ball initially changes their release, bounce judgment or long-range touch. Familiarity and practice matter.

The equipment choice also does not lower the hoop. Both leagues shoot at a 10-foot rim. Other rules differ, including game length and some court markings; our guide to how long WNBA games are separates those changes from the ball specification.

Does a smaller basketball make shooting easier?

Geometrically, a smaller ball leaves more clearance inside the same 18-inch rim. Grip can also feel easier for a player with smaller hands. Neither point proves that changing ball size automatically raises real-game shooting percentages.

A study of 573 European national-team players compared tournament statistics before and after FIBA introduced size 6. It did not find an overall shooting-accuracy improvement; free-throw accuracy fell in the observed data, while three-point attempt volume increased. The researchers also noted limits that prevent the result from answering every question about every player.

The practical conclusion is modest: ball size changes feel and technique, but shooting performance depends on learned mechanics, distance, strength, practice and the individual player. For technique context, see our guides to basketball shooting form and the main types of basketball shots.

Do college and international women’s leagues use size 6?

Yes, size 6 is the nominal standard in NCAA women’s basketball and FIBA women’s competition. It is also common in girls’ youth leagues, although local age rules should always be checked.

The category matches, but exact tolerances do not have to. FIBA’s 2024 equipment rules give size 6 a circumference of 715 to 730 millimetres and a weight of 510 to 550 grams. Those ranges overlap the familiar WNBA-size ball but are not word-for-word copies of the WNBA rule.

FIBA 3x3 uses a special case: a size 6 circumference with size 7 weight. That is another reason to read the competition label rather than assuming every ball called size 6 has identical mass and construction.

Which basketball should you buy?

For WNBA-style practice, buy a size 6, 28.5-inch ball. Then choose the cover for the surface:

• Use an indoor game ball or quality composite ball on hardwood.
• Use an indoor/outdoor or outdoor model on concrete and asphalt; rough courts wear premium indoor covers quickly.
• Check the printed size, because WNBA colors or team branding can appear on recreational products in more than one format.
• Inflate to the manufacturer’s printed range. Do not force a retail replica to a league setting if its own instructions differ.

If you are joining a league, confirm its equipment rule before training exclusively with one ball. Switching between sizes can change timing and touch until your hands adjust. That first-session awkwardness is normal, not evidence that either ball is poorly made.

Players learning the wider game can continue with basketball positions explained and the basketball shot-clock guide. For the league’s business side, the WNBA salary-cap explainer covers a very different WNBA-versus-NBA comparison.