How to Fit the Right Size Exercise Ball for your Seated Core Exercises

How to Fit the Right Size Exercise Ball for your Seated Core Exercises

Physical therapy guide for how to correctly fit your exercise ball size to get the most benefit from your seated core exercises from Your comments and questions are most welcome below!

It’s vital to know how to fit the right exercise ball for your body for seated ball exercises. If you have the wrong size ball you can run the risk of back injury and your core exercises won’t be as effective as they could be for training your abdominal muscles.

The right size exercise ball for you to sit on depends on your weight, your height and the quality of your exercise ball.

Most exercise balls have the ball size printed on them, usually 45 cm, 55 cm, 65 cm, 75 cm
Here is a typical exercise ball size guide however the size guide isn’t always right for everyone, use this as a general guide only as we all have different body weight and limb length differences.

Height and ball size (general recommendation only – you need to check to be sure)

Less than 4’8″ = 45 cm ball
4’8” to 5’3″ = 55 cm ball
5’4” to 5’1″ = 65 cm ball
5’10 to 6’4″ = 75 cm ball

To know the right size ball you need to sit on the top of the ball and look side on to a mirror and follow these steps:

1. Place both of your feet flat on the ground, if your heels are lifting the ball is too big
2. Check that your hips are slightly higher than your knees – this allows you to keep the normal or neutral curve in your lower back. This helps you to avoid straining your back and promote effective core muscle strengthening. If your hips are lower than your knees the ball is too small.
3. Check that the surface of the ball provides you with firm support you when you sit on it. Choose a good quality firm anti burst exercise ball and make sure it’s well inflated and not so soft that you sink into it when you sit on it.

Key Points for choosing the right side exercise ball for seated core exercises:

*Both feet should be flat on the ground
*Your hips should be higher than your knees when viewed from side on
*The exercise ball should feel firm and consist of good quality anti burst ball material

Please feel welcome to comment or question below. If you’d like to receive regular Physical Therapy exercise ball exercises subscribe now.


  1. Hi , thanks for video,…. i habe ready buy a ball with 75 cm ! and i am 1m69…this size is good for me?!
    i I feel that the exercises with this ball are difficult for me

  2. Excuse me, I am conflicting about feet measures
    I am 174 cm hight, my wife 167 cm what sizes better for us ?

  3. height is 5.10"-11" .in 2015 i had sleep disc on left side l5-s1 i am fit nd fine but for stiffness nd extension my doctor told me just lie on your back 5 min then lie on your fron 3 minutes on a swiss ball just for relaxation ..but the problem is which size is perfect for me please chose me to help..

  4. I have a 65cm ball but need a 70 cm ball.
    When the ball is at 65cm it is also very soft and not hard enough. So can I inflate the ball a little bit more? Like 70cm?

  5. Thanks for the video. How much is the minimum your hips should be higher then your knees? I just got a ball and find that if my hips are too much higher, it would put strain on my knees when I hold myself on the top of the ball. However, if they are just tiny bit higher than 90 degrees, I can sit and be stable on the ball without holding myself with my leg muscles. What are your views?

  6. The guide listed here does not account for people between 5’5 and 5’9 ……..whats up with that??

  7. Why did you show us a tape measure and you did not use it so that’s a thumbs down for you because your video and misleading

  8. Hi. I’m 5’0 even, 198 lbs and my inseam is exactly 24" (I don’t know if that matters though). I have a 55cm ball. Is this the correct size? I feel it could be incorrect on certain exercises but okay on others??

  9. hello, thank you for creating this simple guide for us beginners!
    anyway, i am having a bit of dilemma and hope you can help me out? heres the situation:
    i got a 65cm ball for my room to use instead of a desk chair while im on the computer. 65cm was the company’s recommended size to fit a standard desk for most adults between 5ft and 5’ll, but there were separate sizing guidelines for exercise use. i am 5’2 so i am in the 55cm size range for that. i am hoping to get as much use as i can out of the ball i own if possible so here is my question:
    i went through all of these check points a few times and i am able to sit down on top of the ball, plant both feet without rolling forward, and have my hips slightly higher than my knees. so i am able to accomplish these checkpoints, however it requires some adjustment to compensate for my height. when i sit down, i have to draw my ankles/calves back closer to the ball to keep my heels from lifting. is it okay for me to continue with this ball or will i have to invest in a second ball thats smaller?

  10. I think I got the wrong size 85cm my height because I have some fractures went from 5.4 to about 5.3 I let air out of the ball what should I do

  11. I really want to know how on earth they are measuring these balls. Surely 55cm for example is not the circumference of what they say 55cm is. So confused.

  12. I am 5’8”, and weigh 210 lbs. What size ball is the best recommended for my height and weight? Someone in a sports store told me 75cm, but i’m not sure and i don’t want to buy the wrong thing

  13. I am confused you are the only trainer that says your knees need to be lower than your hips. Everybody else recommends 90 degrees angle.

  14. I believe the reason she is saying the exercise ball chart may not be accurate as far as the height guide is because if you have 10 people all the same height I can only guess that the torso and leg length would be different in at least half of them. Sitting on the ball to try it out is the best option although we all do not have that ability.

  15. I’m 4’11 and I got a 55cm balance ball but I notice that my legs are at 90°angle when I sit on it.
    Should I get a bigger size?
    If so, what size?

  16. Hello there, I’m 5 ft tall and 118 lb so I was wondering what size I should get, I’m between the 55cm or 45 cm, could you please help .Thank you

  17. If I were to have my own (bigger) place to live, then I’d wanna get 2 "75-cm." exercise balls so I could sit on one of ’em. I’d wanna play with ’em so I could cuddle, bounce and roll ’em.

  18. I just bought a 65 cm ball (I’m 170cm) as that was recommended on the package for my height. However, I found it too small for sitting at the desk. Those ball size tables are only as reliable as dress sizes. When I placed my hands on the desk my elbows were lower than my wrists and I felt I needed to reach up with my upper body to have my head and shoulders at the right height. So – one more piece of advice, if you want to use it in the office check also the height of your desk. Best thing to do is to ask in the shop if you can return the ball if needed as you’ll really only see if it’s the right size when you try it. I took mine back and swapped it for a 75 cm one which I’m happy with.
    Btw I really liked the video, nice and clear explanation, thanks! Looking forward to watching the other vids on your channel.

  19. I am actually female and I was hesitant about the 75cm because I tried an inflated one in another sport store that was either not fully inflated or maybe I was nervous about putting my full weight on it because it kept sinking. I sat on a 65cm ball in my company’s gym and my hips are parallel with my knees at a 90 degree angle with my feet flat on the ground. Is that bad or food and does your recommendation remain the same of the 75cm?

  20. Hello I. Pregnant.. 5ft7/8 and about 13 stone .. I have long legs so should I get a 75cm ball ?

  21. Hi Michelle
    I’m having trouble buying the right size fit ball. I have very long legs and a short torso. Length from my hips to armpits when sitting is 35cm and my legs are approx 90cm. Overall I’m 170cm tall and weigh 58kg, so wouldn’t need to support much weight on it. The table I work at is 71cm high. I have a 75cm ball, but it is too low. There are no shops in my area that stock +75cm balls so I can’t try them out. If I was to buy one online is there a size you would recommend based on these measurements?

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