Written by

Gina Conley, MS

September 18, 2025

How to Choose the Best Size Birth Ball for Pregnancy and Labor

Birth, Birth Preparation, Pregnancy

When it comes to preparing for pregnancy, labor, and postpartum recovery, one of the most versatile tools you can add to your toolkit is a birth ball. But a common question I hear as a perinatal fitness trainer and birth doula is: “What size birth ball should I get?”

Since the wrong size ball can make sitting, exercising, or laboring uncomfortable, let’s break down exactly how to choose the right one for your body.

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Why Size Matters

The main goal when using a birth ball is comfort and mobility. The correct size allows you to:

Keep your hips slightly higher than your knees.
Plant your feet firmly on the floor for stability.
Have enough space for your belly without compression.
Move your hips freely to find relief and comfort.

If the ball is too big, your feet may barely touch the ground, leaving you unstable. If it’s too small, your knees and hips may be misaligned, reducing mobility and potentially adding pressure on your belly.

General Size Guidelines

Birth balls come in several sizes, measured in centimeters. Here’s a quick guide:

Medium (48–55 cm): Best for people 5’3” and under.
Large (58–65 cm): Best for people 5’4” to 5’9”.
Extra Large (68–75 cm): Best for people 5’10” and taller.

👉 Keep in mind: Your torso and leg length also matter. If you have a long torso, you may need to size up. If you have shorter legs compared to your torso, sizing down could be more comfortable.

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How to Check if Your Ball Fits

Once your ball is inflated, sit down and notice:

✅ Hips higher than knees: This helps open your pelvis and allows easier movement.
✅ Feet flat on the ground: Stability is key for comfort.
✅ Belly has space: You should feel supported, not cramped.

Too Big? You’ll be on your tiptoes or wobbling. Try deflating slightly or switching to a smaller ball.
Too Small? Your hips will be lower than your knees, limiting movement. Add more air or size up.

Birth Balls in Labor

You’ll use your ball for more than just sitting. It can support different laboring positions, such as leaning forward in tabletop or resting on it during contractions.

If the ball is too big, you may feel awkwardly elevated.
If the ball is too small, you may feel like you’re tipped forward or too low to the ground.

The right size keeps you comfortable in multiple positions, both sitting and leaning.

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A post shared by Gina, MS, & Roxanne, RN, BSN (@mamastefit)

Should You Bring Your Own to the Hospital?

Most hospitals stock a variety of birth ball and peanut ball sizes. But it’s always okay to ask for a different size if the one in your room doesn’t feel right.

That said, having your own ball at home is extremely valuable:

Great for prenatal workouts.
Helps with early labor at home.
Perfect for postpartum soothing (many parents love gently bouncing with their baby on a ball).

Since birth balls are affordable and multi-purpose, I highly recommend investing in one for both pregnancy and beyond. Check out our favorite birth ball from Trideer and use our code MAMASTEFIT05 for a little extra savings.

Final Tips

When in doubt:

Aim for hips slightly higher than knees.
Consider your height and your proportions.
Adjust by inflating or deflating as needed.

Choosing the right size birth ball can make a huge difference in your comfort during pregnancy, labor, and recovery.

If you’d like to dive deeper into how to use a birth ball for labor comfort measures, partner support, and positioning, check out our online childbirth education courses (use code YouTube10 for 10% off!).