Buying a hat online for a kid you can't see or measure in the shop is a bit of a leap of faith. Age on the box doesn't always match age on the head, and "one size fits most" tends to mean "one size fits nobody in this house". The good news is a kid's hat only needs one number to get right: head circumference. Everything else follows from there.
Here's the full sizing guide, and the thirty-second way to measure it properly.
Kids hat sizes by age
Age is the starting point, not the final word. Kids grow at wildly different rates, and a big-for-their-age one year old can easily measure into the M or even L range. If your kid's actual head measurement lands between two rows, the general rule is to size up rather than down. A hat with a little room to grow gets worn all season. A hat that's already tight in week one gets left on the hook by week three.
The thirty-second measurement
You don't need a sewing kit for this, just a soft tape measure or a plain piece of string.
-
Wrap it around the widest part of your child's head, roughly where a hat would naturally sit, just above the eyebrows and ears.
-
Keep it snug against the head without pulling tight. You're measuring the head, not compressing it.
-
If you're using string, mark where it meets itself, then lay it flat against a ruler to get the number in cm.
-
Match that number to the chart above.
That's genuinely the whole method. No fancy tools, no guesswork, and it holds up better than going off age alone. Prefer watching it done? We walked through it on Instagram too.
Why the brim depth matters too
Head size gets a hat on. Brim depth is what actually does the shading once it's there. As kids size up through S to XL, the brim grows with them, because a toddler's face and shoulders need more coverage than a baby's, not less. It's worth checking both numbers if your kid is between sizes, since a hat with the right head size but a shallow brim isn't giving the coverage the age range assumes.
When to re-measure
Heads don't grow on a fixed schedule, but a quick re-measure every few months keeps you ahead of it, especially through the fastest growth windows in the first two years. A good moment to check: whenever a hat starts leaving a mark on the forehead or sliding down further than it used to.
Measure once, use it everywhere
Once you've got your kid's head measurement, keep it somewhere you'll actually find it again, a note in your phone works fine. It's the number every future hat purchase comes back to, ours included. The full chart and the same measuring method live permanently on our Find Their Fit page, so it's always there when the next size-up rolls around.
Kids hats that finally stay put, so you can, too.
Frequently Asked Questions
Q1. How do I measure my child's head for a hat without a tape measure?
Wrap a piece of string around the widest part of the head, just above the eyebrows and ears, mark where it overlaps, then lay it flat against a ruler to get the measurement in centimetres. It takes about thirty seconds and is just as accurate as a tape measure.
Q2. What size hat does a 2 year old need?
Most 2 year olds sit in the size M to L range, roughly 50 to 52 cm head circumference, but this varies more than people expect at this age. Measuring directly is more reliable than going off age alone, especially if your child has always run big or small for their age.
Q3. Should I size up if my child is between two hat sizes?
Generally yes. A slightly roomy hat gets worn through a full growth spurt, while a snug one is often outgrown within weeks. If they're right on the border between two rows in the chart, the larger size is usually the safer buy.
Q4. How often should I re-measure my child's head?
Every few months is a reasonable habit, particularly under 2 years old when growth is fastest. A hat leaving marks on the forehead or sliding down more than it used to is a good practical sign it's time to check again.
Related posts:
How to Keep a Hat on a Toddler (And Actually Keep It There) · What Does UPF 50+ Actually Mean?
Kids Hat Sizes by Age: The Measure-Once Guide
Buying a hat online for a kid you can't see or measure in the shop is a bit of a leap of faith. Age on the box doesn't always match age on the head, and "one size fits most" tends to mean "one size fits nobody in this house". The good news is a kid's hat only needs one number to get right: head circumference. Everything else follows from there.
Here's the full sizing guide, and the thirty-second way to measure it properly.
Kids hat sizes by age
Age is the starting point, not the final word. Kids grow at wildly different rates, and a big-for-their-age one year old can easily measure into the M or even L range. If your kid's actual head measurement lands between two rows, the general rule is to size up rather than down. A hat with a little room to grow gets worn all season. A hat that's already tight in week one gets left on the hook by week three.
The thirty-second measurement
You don't need a sewing kit for this, just a soft tape measure or a plain piece of string.
Wrap it around the widest part of your child's head, roughly where a hat would naturally sit, just above the eyebrows and ears.
Keep it snug against the head without pulling tight. You're measuring the head, not compressing it.
If you're using string, mark where it meets itself, then lay it flat against a ruler to get the number in cm.
Match that number to the chart above.
That's genuinely the whole method. No fancy tools, no guesswork, and it holds up better than going off age alone. Prefer watching it done? We walked through it on Instagram too.
Why the brim depth matters too
Head size gets a hat on. Brim depth is what actually does the shading once it's there. As kids size up through S to XL, the brim grows with them, because a toddler's face and shoulders need more coverage than a baby's, not less. It's worth checking both numbers if your kid is between sizes, since a hat with the right head size but a shallow brim isn't giving the coverage the age range assumes.
When to re-measure
Heads don't grow on a fixed schedule, but a quick re-measure every few months keeps you ahead of it, especially through the fastest growth windows in the first two years. A good moment to check: whenever a hat starts leaving a mark on the forehead or sliding down further than it used to.
Measure once, use it everywhere
Once you've got your kid's head measurement, keep it somewhere you'll actually find it again, a note in your phone works fine. It's the number every future hat purchase comes back to, ours included. The full chart and the same measuring method live permanently on our Find Their Fit page, so it's always there when the next size-up rolls around.
Kids hats that finally stay put, so you can, too.
Frequently Asked Questions
Q1. How do I measure my child's head for a hat without a tape measure?
Wrap a piece of string around the widest part of the head, just above the eyebrows and ears, mark where it overlaps, then lay it flat against a ruler to get the measurement in centimetres. It takes about thirty seconds and is just as accurate as a tape measure.
Q2. What size hat does a 2 year old need?
Most 2 year olds sit in the size M to L range, roughly 50 to 52 cm head circumference, but this varies more than people expect at this age. Measuring directly is more reliable than going off age alone, especially if your child has always run big or small for their age.
Q3. Should I size up if my child is between two hat sizes?
Generally yes. A slightly roomy hat gets worn through a full growth spurt, while a snug one is often outgrown within weeks. If they're right on the border between two rows in the chart, the larger size is usually the safer buy.
Q4. How often should I re-measure my child's head?
Every few months is a reasonable habit, particularly under 2 years old when growth is fastest. A hat leaving marks on the forehead or sliding down more than it used to is a good practical sign it's time to check again.
Related posts:
How to Keep a Hat on a Toddler (And Actually Keep It There) · What Does UPF 50+ Actually Mean?