Kids Clothing Size Calculator
Estimates children's clothing size from height, chest, waist and age.
Your measurements
Stand straight without shoes.
Around the fullest part of the chest.
Around your natural waistline.
Around the fullest part of your hips/seat.
Your estimated size
Enter your measurements and press Estimate size to see a recommended size range. Sizing varies by brand.
Before you rely on this: Use this as a quick guide and check the result against your own working before you rely on it.
How to use this calculator
- Enter the child's height (the most important measurement).
- Add chest and waist; hip is optional.
- Pick the size system to show and press Estimate size.
How it works
The Kids Clothing Size Calculator estimates a children's clothing size from height, chest and waist, showing AU, US and EU (height-cm) equivalents.
For children, height and body measurements predict size far better than age, because kids grow at very different rates. The tool weights height most heavily, then chest and waist, and notes that children between sizes are usually better in the next size up.
Worked example
120 cm tall child. A child around 120 cm tall is typically a size 6 (US 6, EU 116) — but check chest and waist, and size up if they are growing fast.
Tips
- Measure height against a wall without shoes.
- Keep a note of measurements with the date — kids grow fast.
Frequently asked questions
Should I use age or measurements?
Use measurements. Age-based sizes are only a rough guide because children of the same age vary widely in height and build. Height first, then chest and waist.
My child is between sizes — which do I pick?
Children grow quickly, so the next size up usually lasts longer and is the safer choice for most everyday clothing.
How accurate are these size results?
They are a helpful starting point, not a guarantee. Brand sizing, garment cut, fabric stretch, body shape and measurement technique all change the best fit, so we show a recommended size plus adjacent sizes rather than one exact answer.
Related tools
- Clothing Size Finder
- Shoe Size Calculator
- Dress Size Calculator
- Bra Size Calculator
- Jeans Size Calculator
- Shirt Size Calculator
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Cite this tool
Zerdly. (2026). Kids Clothing Size Calculator. Retrieved from https://www.zerdly.com/tools/kids-clothing-size-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.