Exercise Ball Size Chart: What Size Ball for Your Height

Exercise ball size chart by height

Each column is one publisher's chart, in its own words, with the centimetre equivalent. A dash means that chart has no ball of that size. Ball size is the diameter when fully inflated.

• TheraBand: TheraBand's Pro Series support page uses the same height bands but lists the blue ball as 74 cm rather than 75 cm.
• Gaiam: Gaiam's adult chart has three sizes only. Its older balance-ball FAQ gives the 75 cm band as 6'0" – 6'3".
• Trideer: Trideer's own weight-limit guide prints a different chart (55 cm at 5'1" – 5'8", 65 cm at 5'9" – 6'2"). We use the dedicated size guide.
• ACE: ACE is a fitness-certification body, not a ball maker; its chart stops at 75 cm.

Where the charts agree, and where they split

The same four charts read the other way round: your height, and the size each one gives. Rows marked “split” are the heights where brands disagree, which is where the sit test matters most.

Heights are whole inches; a dash means that chart publishes no band there (Gaiam's adult chart runs 5'0" to 6'5", and Trideer's leaves 4'7" to 4'10" unassigned).

Check the fit: the sit test

Every chart above is a starting point (Gaiam calls its own chart a guideline), and Trideer's size guide gives the seated test that settles it:

1. Inflate the ball fully first (see inflation tips); a soft ball reads a size small.
2. Sit on the ball with your feet flat on the floor.
3. Your hips should be level with or slightly higher than your knees.
4. Your knees should be at about 90 degrees, or slightly more, with thighs parallel to the floor or sloping slightly down.

Between sizes? Trideer's guide says to take the larger size for training and the smaller for office sitting. Gaiam adds that experienced users may find a larger or smaller ball works for them.

Sizing a ball as a desk chair

At a desk, the desk sets the seat height as much as your legs do. Gaiam says a balance ball can generally be used as a seat, and that whether it suits a desk depends on your height and the desk's height.

• Standard 28–30 in desk: Trideer recommends a 65 cm ball for most users from 5'5" to 5'11".
• Lower desk or shorter user: 55 cm, per Trideer.
• Higher desk or taller user: 75 cm, per Trideer.
• Ball chairs with a base are smaller: Gaiam's Classic Balance Ball Chair uses a 52 cm ball for people 5'0" to 5'11" and lists a 24–25 in sitting height.

The calculator's desk mode applies the same rule: it starts from your height-chart size and moves one size up or down for a desk above 30 in or below 28 in.

Inflation tips

• Mark the wall. Gaiam suggests a pencil mark at the ball's size (55, 65 or 75 cm) and inflating until the top of the ball is level with it.
• Don't go past the stated size. Gaiam warns a ball inflated beyond the size on the box could burst.
• Inflate twice. Gaiam says a new ball may need re-inflating once or twice over a day or two as the material stretches; Trideer suggests 80% first, a 24-hour rest, then full.
• Measure it. Trideer says a correctly inflated ball measures its stated diameter and compresses about 2–3 in when you sit.
• Top it up. ACE notes balls lose size over time as air escapes; Trideer adds that they expand in heat and shrink in the cold.
• Pump. TheraBand recommends a high-volume pump for its Pro Series balls and includes an adapter for a standard air compressor.

Weight and burst ratings: read the label carefully

Brands quote different kinds of number, so they don't compare directly. Trideer's weight-limit guide draws the line: the weight limit is the maximum recommended user weight, while burst resistance is the most the ball can theoretically hold and is usually much higher. It says to follow the weight limit.

Note that Trideer's two pages quote different figures (2,200 lb and 330 lb), and neither is labelled as a user weight limit. Check the specific ball's listing for its user-weight rating before you buy.

How this calculator works

• Your height is matched against each of the four charts above, using the bands exactly as published. A band printed as 5'1"–5'6" covers everyone up to just under 5'7". Centimetres are converted at 2.54 cm per inch.
• The size most charts name is the answer. When the charts tie (for example 5'6": two say 55 cm, two say 65 cm), it follows Trideer's border rule: the larger size for exercise, the smaller for desk sitting.
• Desk mode then moves one size up for a desk above 30 in or one size down below 28 in, per Trideer's desk guidance.
• A chart with no band for your height is shown as “no band” and left out of the count. We never fill a gap with a guess.
• Everything runs in your browser. Nothing you enter is stored or sent.

This is gear sizing for exercise and desk sitting only. It doesn't cover therapy or other specialist uses of a ball.

Exercise ball size FAQ

What size exercise ball do I need for my height?

Gaiam's chart puts a 55 cm ball at 5'0" to 5'5", 65 cm at 5'6" to 5'11" and 75 cm at 6'0" to 6'5". Trideer's chart is within an inch of that, while TheraBand and ACE start the 65 and 75 cm sizes 1 to 4 inches taller.

What size exercise ball if I'm 5'6" or 5'7"?

This is where the charts split. At 5'6" Gaiam and Trideer say 65 cm while TheraBand and ACE say 55 cm; at 5'7" only ACE still says 55 cm. Sit on the ball: if your knees end up above your hips, go up a size.

What size exercise ball for a 6 foot person?

Gaiam and Trideer put 6'0" on a 75 cm ball; TheraBand (65 cm to 6'1") and ACE (65 cm to 6'3") say 65 cm. Either can fit, so the sit test decides: hips level with or slightly above your knees.

What size exercise ball should I use as a desk chair?

Trideer says desk height matters as much as your height: a 65 cm ball for most 5'5" to 5'11" users at a standard 28 to 30 inch desk, a size down for a lower desk and a size up for a higher one. Gaiam's own ball chair uses a 52 cm ball in a base for people 5'0" to 5'11".

How do I know if my exercise ball is inflated enough?

Gaiam suggests a pencil mark on the wall at the ball's size (say 65 cm) and inflating until the top of the ball is level with it, and not past the size on the box. Trideer says a correctly inflated ball should measure its stated diameter and compress about 2 to 3 inches when you sit.

What does an anti-burst or burst rating on an exercise ball mean?

Trideer describes anti-burst as a ball that deflates slowly if punctured, and separates the user weight limit from burst resistance, which it says is usually much higher. Brands quote different figures: TheraBand states 600 lb of static weight and Gaiam a 300 lb weight capacity.

Sources

Last checked: October 26, 2026. Each page was opened and read; height bands are copied as published.

• THERABAND Standard Exercise Balls (Performance Health): size chart (manufacturer)
• Gaiam Total Body Balance Ball Kit (product page sizing): size chart (manufacturer)
• Trideer: Exercise Ball Size Guide (Dec 25, 2025): size chart (manufacturer)
• American Council on Exercise: "Play Ball!" (ACE Certified News, May 2013): size chart (certifying body)
• TheraBand Pro Series SCP Exercise Balls: support article (sizes, inflation)
• Gaiam: Top 10 Balance Ball, Exercise Ball & Stability Ball FAQs (inflation, seat use)
• Gaiam Classic Balance Ball Chair (52 cm ball, inflation instructions)
• Trideer: Exercise Ball Weight Limit Guide