A dad came in last September with his daughter, who was seven, and a plan he was pleased with. He wanted the 25in racket, because she would grow into it and he would not be back next summer buying another one. Perfectly sensible logic, applied to school shoes and winter coats for generations. Applied to a tennis racket, it is the single most expensive mistake a parent can make, and the cost is not measured in money.
We talked, she held a 23in, took two shadow swings with an actual shoulder turn instead of a heave, and the conversation was over. Here is the reasoning behind that, and the sizes to work from.
Measure the child, not the birthday
Junior rackets are sold in lengths, running from 19in through 21in, 23in and 25in to 26in, before a player moves to a standard adult 27in frame. Age is the label everyone uses because it is easy, but height is what actually decides the fit. Two nine-year-olds can be 20cm apart, and the racket does not know how old anybody is.
The bands below are the conventional guidance used across UK coaching programmes. Treat them as a starting point and check against the child in front of you.
| Racket length | Approximate height | Typical age |
|---|---|---|
| 19in | Up to about 100cm | Around 3 to 5 |
| 21in | About 100 to 110cm | Around 4 to 6 |
| 23in | About 110 to 125cm | Around 6 to 8 |
| 25in | About 125 to 140cm | Around 8 to 10 |
| 26in | About 140 to 150cm | Around 9 to 11 |
| 27in (adult) | Over about 150cm | 11 and upwards |
There is a physical check that takes five seconds and settles most cases. Stand the child upright, have them hold the racket down by their side with a relaxed arm and the head pointing at the floor. The head should hang just clear of the ground. If it is planted on the floor, or the child has to lift their shoulder to keep it off, the racket is too long.
What a racket that is too big actually costs
Children are adaptable, and that is the problem. Give a child a frame that is too long and too heavy and they will find a way to hit the ball with it. They just find the wrong way.
Watch what happens. They choke up the grip, holding it halfway along the handle to shorten the lever, which means they never learn where their hand belongs. The racket head drops below the wrist on the forehand because they cannot hold it up. The swing becomes all arm, with no shoulder turn and no legs, because rotating the body with something that heavy out in front of them is too slow. The serve turns into a poke, since a proper throwing action needs a racket they can accelerate. And they arrive late to every ball, which stops them moving their feet, because there is no point setting up early if you cannot swing anyway.
Those are not phases they grow out of when the racket finally fits. They are habits, and a coach will spend two years unpicking what an oversized racket taught in six months. A 21in frame outgrown in a year is not wasted money. It is the cheapest coaching you will ever buy.
Buying well, and knowing when to move up
A few things worth checking before you pay, none of which appear on the label:
- Weight, not just length. Junior frames are aluminium and light for a reason. If two rackets are the same length, the lighter one is almost always the better buy for a child under about ten.
- Grip size. Junior grips are small by design. A child should be able to close their hand fully around the handle with a small gap between fingertips and palm. An overgrip is a cheap way to add a fraction if it feels lost in their hand.
- Ready-strung. Junior rackets come strung, and at these lengths there is rarely any reason to change anything. Save the stringing decisions for when they reach a 26in or adult frame.
- The right ball. The racket length is only half the setup. Red, orange and green stage balls pair with the shorter frames and smaller courts, and the coach will tell you which stage the child is on.
- Footwear. Running trainers slide on court and offer nothing sideways. Proper tennis shoes matter more for a growing child than an upgraded frame does.
One more thing parents ask about constantly: siblings. Passing a racket down works well, provided you pass it down when the younger child fits it rather than when the older one finishes with it. A frame sitting in the garage for a year is fine. A seven-year-old using a nine-year-old's racket is not.
On timing the move up: go when the child has outgrown the racket, not when they have outgrown the box it came in. Signs are easy to spot once you know them. They are hitting the ball comfortably in front, the racket looks short in their hand rather than long, and they are starting to swing faster than the frame can usefully carry. If they are still fighting the current racket, another inch will not help.
If you are unsure, bring the child in with you. Two minutes of holding a couple of frames from the racket range tells us more than any height chart, and it is far better than guessing from a screen. If they already have a coach, ask them first. They see the swing every week and their opinion is worth more than ours.