To play basketball properly, you need the right sized ball.

That’s because, playing with a ball that’s too big or too small often leads to poor technique and bad shooting habits. It’s important to feel in control of the ball so you can handle it correctly, which is why a good grip is crucial. Using the right sized basketball will help you feel more confident and could enhance your game, so it’s important to take time to understand what size basketball you need.

To practice basketball, you will also require specific balls for different environments. Whether you’re playing on an indoor court or outside in the park with family and friends, you’ll need the correct type of basketball - whatever your level.

There are many types and sizes of basketball available, and if you’re unsure what ball you should be using, check out our basketball size guide to get to grips with everything you need to know to practice like a pro - with our handy chart to help you understand what size is best for you.

What is the difference between indoor and outdoor basketballs?

Basketballs can be made from different materials such as traditional genuine leather, synthetic leather, composite leather, rubber and technical plastics. And what material you go for will depend on whether you are going to be practicing basketball indoors or outdoors.


For indoor players and regular practice, opt for a genuine leather ball that will provide a good game on the wooden and synthetic flooring used on indoor basketball courts. But be aware that a leather ball may be slick when first used and generally needs to be “broken in” by being practiced with before using it in an actual game. And because of the materials used, a good indoor basketball will generally cost you more than an outdoor ball.

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Basketballs made of rubber or technical plastics are more resistant and more durable on abrasive materials such as tarmac, asphalt, concrete and gravel. This makes them perfect for using outdoors on rougher ground. They do not need to be broken in and are ready for immediate use right out of the box. The rubber or composite material is not slick or slippery, but can feel heavier and harder than an indoor ball.

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Indoors and outdoors

If you want to practice both in the gym and outside, choose a synthetic leather basketball that offers good rebound combined with great resistance. Just make sure you choose the right basketball size for the age and gender of the players.

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What basketball size do I need?

The orange ball used in basketball was originally made with eight pieces of leather assembled around a tube. Today, the technology and innovations allow multiple combinations to suit your needs. Basketballs also come in a variety of sizes depending on the age and gender of the player, so it’s important to get the right size according to your needs.

Size 1 basketballs - what is a size 1 basketball and who is it best suited for?

Size 1 is a novelty-sized, or 'micro-mini' basketball that is suitable for children aged 2 to 4 years old. A size 1 basketball has a circumference of 16" (40.6cm) and weighs 8oz.

Size 3 basketballs - what are they and who are they best suited for?

Size 3 is a novelty-sized, or 'mini' basketball that is suitable for all ages, particularly for children aged 4 to 6 years old. A size 3 basketball has a circumference of 22" (55.9cm) and weighs 10oz.

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Size 5 basketballs - what are they and who are they best suited for?

Size 5 is the standard basketball size for both boys and girls aged 7 to 10 years old. A size 5 basketball has a circumference of 27.5” (69.5cm) and weighs 17oz.

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Size 6 basketballs - what are they and who are they best suited for?

A size 6 basketball is suitable for girls from 10 years old, and it’s the official size of the WNBL (Women's National Basketball League) Basketball. It’s also suitable for boys aged 10 to 12 years old. It has a circumference of 28.5” (72cm) and weighs 20oz.

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Size 7 basketballs - what are they and who are they best suited for?

Size 7 is the official size of all adult basketballs, suitable for male basketball players aged 12 years and over. Size 7 balls have a circumference of 29.5” (75cm) and weighs 22oz. The Spalding NBA Triple Double Basketball is a size 7 basketball and an ideal choice for competitive players - suitable for both indoor and outdoor courts.

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Basketball Size Guide


Basketballs vary in weight as well as circumference, so it’s important to get the right size for the player. A size 7 ball is more than twice the weight of a size 3 mini, which makes a huge difference when shooting. This extra weight will make it very difficult for young children to shoot with proper technique.

You should also ensure that any basketball is inflated correctly, as a ball that is overinflated or underinflated will affect the playing experience. The recommended pressure is clearly marked on the ball by the manufacturer, and you should ideally use a pump with a pressure gauge for precise inflation.

So, what size basketball should you choose? Beginners, kids and anyone looking to improve should opt for smaller balls that are easier to hold onto, pass and catch. While regular players who want to play proper games will need a full-size basketball (size 7).

Check out our full range of basketballs to suit your age and environment.

At Decathlon, we believe that sport is for everyone and you don’t have to spend a lot to get involved. We can help you choose the ideal basketball according to your age and the environment you’re playing in, so you can really slam dunk your way to the top of your game. And we've kept our prices low, too! But for the most dedicated fans, we also stock some special NBA-approved basketballs - so there really is something for everyone!