LIFTY // JOURNAL
Kids' Bike Size Guide Ireland: What Size Bike for My Child? (Age & Height Chart)
Buying a child's bike for Christmas? Kids' bikes are sized by wheel size, not frame size, and a bike that's too big is the most common mistake parents make. It's harder to control, harder to stop and knocks confidence. Use the chart below as a starting point, then check your child's inside leg against the bike's seat height.
Quick answer: As a guide, a balance bike suits ages 2–4, a 14" bike ages 3–5 (about 94–109 cm tall), 16" ages 4–6 (about 104–117 cm), 20" ages 5–9 (about 114–130 cm), 24" ages 7–12 (about 130–140 cm), and 26" or a small adult bike from about 140 cm. Height and inside leg matter more than age. Your child should be able to sit on the saddle with the balls of both feet on the ground.
Kids' bike size chart by age and height
| Wheel size | Typical age | Typical child height | Examples at Lifty |
|---|---|---|---|
| Balance bike (12") | 2–4 | about 85–100 cm | Giant Pre balance bike |
| 12" | 2½–4 | about 86–102 cm | Romet Tom 12, Tabou Miss ST, S'COOL XXlite |
| 14" | 3–5 | about 94–109 cm | Tabou Miss CS, Tabou Royal Space Shark |
| 16" | 4–6 | about 104–117 cm | Giant ARX 16, Bobbin Gingersnap, S'COOL niXe 16 |
| 18" | 5–7 | about 110–122 cm | S'COOL niXe 18, Tabou Rocket CS Alu |
| 20" | 5–9 | about 114–130 cm | Giant ARX 20, Liv Tempt 20, Romet Rambler 20 |
| 24" | 7–12 | about 130–140 cm | Giant ARX 24, Liv Tempt 24, Romet Panda 1 |
| 26" / 27.5" youth | 9–14+ | from about 140 cm | Giant ARX 26, Romet Rambler R6.0 JR, Tabou Venom 1.0 |
These ranges follow the size charts published by major kids' bike makers and overlap on purpose. Each brand's fit is slightly different, so check the product page or ask us. See every size in our kids' bikes collection.
How to measure your child (2 minutes)
- Height: shoes off, back against a wall, mark the top of the head.
- Inside leg: stand them against the wall in socks, put a hardback book between their legs spine-up (like a saddle), and measure from the top of the book to the floor.
- Compare with the bike's minimum seat height. For a beginner, the lowest seat height should be at or just below their inside leg, so both feet can touch the ground. A confident rider can have the seat 3–5 cm higher, with tiptoes down.
Balance bike or stabilisers?
Most children who start on a balance bike learn to ride a pedal bike faster, because they've already learned to balance and steer. Stabilisers teach pedalling but not balance, and many children find it hard to come off them. A common path is a balance bike from about age 2, then straight onto a 14" or 16" pedal bike at around 4–5 without stabilisers.
Should I buy a size up so they grow into it?
It's tempting, but we don't recommend it. An oversized bike is heavier, harder to reach the brakes on and harder to put a foot down from, so children ride less and fall more. If your child is between two sizes, choose the smaller wheel for a nervous or new rider, and the larger one only if they're confident and their inside leg already reaches the lowest seat height. A well-made aluminium bike also resells or hands down well.
Weight, brakes and gears by age
- Weight: try to keep the bike under about 40% of your child's body weight. Aluminium and magnesium frames (Giant ARX, Liv Tempt, Tabou MG, S'COOL XXlite) are much lighter than steel.
- Brakes: 12–16" bikes often have a coaster (back-pedal) brake plus a hand brake. From 16–20", look for short-reach hand levers that small hands can squeeze.
- Gears: single-speed is best up to about 16". Gears become useful from 20", where bikes such as the Romet Rambler 20 and Liv Tempt 20 add Shimano gearing for hills.
- Suspension: heavy suspension forks on small bikes mostly add weight. Light, rigid forks are better for most children, except on proper trail bikes such as the Giant STP 20.
What about an electric bike or e-scooter for a child?
Under-18s can't ride e-scooters in public in Ireland since 2 October 2026, and the RSA asks parents not to buy them for children. A pedal bike or balance bike is the safe, legal choice. Read our parents' guide: what's legal for under-18s.
Christmas buying tips
- Add a helmet that fits: measure head circumference just above the eyebrows. See our bike helmets.
- Add lights for winter afternoons. Front and rear lights are a legal requirement for riding in the dark. See bike lights.
- Order early. Popular sizes sell out before Christmas, and some bikes are ordered in for you, so check delivery times on the product page.
- Come to the showroom at 157 Capel Street, Dublin 1, for a fit check (Tue–Fri 11:30–18:00, Sat 11:30–17:00).
- Buying for yourself as well? Your own bike may qualify for the Cycle to Work scheme.
Frequently asked questions
What size bike for a 5-year-old?
Most 5-year-olds ride a 14" or 16" bike. Children around 104–117 cm usually fit a 16". Check that they can touch the ground with both feet from the saddle.
What size bike for a 7-year-old?
Usually an 18" or 20" bike. Children about 114–130 cm tall typically fit a 20".
What size bike for a 10-year-old?
Most 10-year-olds ride a 24" bike (about 130–140 cm tall). Taller 10-year-olds may fit a 26" youth bike.
What age is a 20-inch bike for?
Typically ages 5–9, or a child height of about 114–130 cm. Height and inside leg matter more than age.
What age is a balance bike for?
Most children start on a balance bike at around 2 to 3 years old and move to a pedal bike at around 4 to 5.
Is it OK to buy a bike one size too big?
It's better not to. An oversized bike is harder to control and stop. If your child is between sizes and still learning, choose the smaller size.
Do kids need a helmet on a bike in Ireland?
Helmets aren't legally compulsory for cyclists in Ireland, but they're strongly recommended, especially for children.
Size ranges are typical guides based on published kids' bike size charts from major manufacturers; each model fits slightly differently. Checked 12 November 2026.
