Bike size guide

An 18 inch bike suits a rider of about 122 to 147cm, usually 7 to 11 years old, on an 18 to 18.5 inch top tube. It is the last step before a full size 20 inch.

Rider heightWheel sizeTop tube
60 to 91cm12"12 to 12.5"
81 to 106cm14"14 to 14.5"
96 to 122cm16"16 to 16.5"
122 to 147cm18"18 to 18.5"
147 to 157cm20"19.75 to 20.25"
157 to 168cm20"20 to 20.5"
168 to 175cm20"20.25 to 20.75"
175 to 183cm20"20.5 to 21"
183 to 190cm and up20"20.75 to 21.5"
160cm and up22"21 to 22.25"
160cm and up24"21.75 to 22"
160cm and up26"22 to 23"

Sizes overlap on purpose, so personal preference comes into it. If your rider is near 147cm and still growing, look at a 20 inch instead: it is the size they will keep riding.

How to measure

Stand your rider against a wall in the shoes they ride in, heels flat, and mark the top of their head. Measure from the floor to the mark.

  • Between an 18 and a 20? Take the 20. It is the size they will keep riding, and an 18 gets outgrown quickly.
  • They should be able to stand over the top tube with both feet flat on the ground.

Not sure? Send us their height and we will tell you what we would put them on.

Bike size guide

An 18 inch bike suits a rider of about 122 to 147cm, usually 7 to 11 years old, on an 18 to 18.5 inch top tube. It is the last step before a full size 20 inch.

Rider heightWheel sizeTop tube
60 to 91cm12"12 to 12.5"
81 to 106cm14"14 to 14.5"
96 to 122cm16"16 to 16.5"
122 to 147cm18"18 to 18.5"
147 to 157cm20"19.75 to 20.25"
157 to 168cm20"20 to 20.5"
168 to 175cm20"20.25 to 20.75"
175 to 183cm20"20.5 to 21"
183 to 190cm and up20"20.75 to 21.5"
160cm and up22"21 to 22.25"
160cm and up24"21.75 to 22"
160cm and up26"22 to 23"

Sizes overlap on purpose, so personal preference comes into it. If your rider is near 147cm and still growing, look at a 20 inch instead: it is the size they will keep riding.

How to measure

Stand your rider against a wall in the shoes they ride in, heels flat, and mark the top of their head. Measure from the floor to the mark.

  • Between an 18 and a 20? Take the 20. It is the size they will keep riding, and an 18 gets outgrown quickly.
  • They should be able to stand over the top tube with both feet flat on the ground.

Not sure? Send us their height and we will tell you what we would put them on.

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Raven Trickster 18 Inch Bike
Sale price From

$364.99 AUD

Regular price

$398.99 AUD

or $91.24 a fortnight
Wethepeople CRS 18 Inch Bike

$999.99 AUD

or $249.99 a fortnight
Radio Dice 18 Inch Bike

$749.99 AUD

or $187.49 a fortnight
Radio Saiko 18 Inch Bike
From

$699.99 AUD

or $174.99 a fortnight
Sunday Primer 18 Inch Bike (2025)
Sale price

$799.99 AUD

Regular price

$859.99 AUD

or $199.99 a fortnight
Division Blitzer 18 Inch Bike

$449.99 AUD

or $112.49 a fortnight
Kink Kicker 18 Inch Bike (2027)
Sale price

$719.99 AUD

Regular price

$748.99 AUD

or $179.99 a fortnight
Sunday Primer AL 18 Inch Bike

$849.99 AUD

or $212.49 a fortnight
Wethepeople Aerox 18 Inch Bike

$1,299.99 AUD

or $324.99 a fortnight
Fit Bike Co Misfit 18 Inch Bike

$949.99 AUD

or $237.49 a fortnight
Radio Revo Pro 18 Inch Bike

$599.99 AUD

or $149.99 a fortnight

LUXBMX carries Australia's biggest range of Freestyle & Race BMX Bikes, we stock all brands and models that we believe in, and truly stand by every Bike you see listed. We have Bikes available for every budget, and be sure to reach out if you need any further expert advice...