We all know the health benefits of riding a bike. Making sure your bike is the correct size for you will mean you’re more likely to ride efficiently, enjoy the experience and make it less likely you’ll give up.

Choosing your correct bike size depends on the type of bike, your height, your riding style, and your preference. There’s no substitute for sitting on the bike and riding it, but this guide will give you a flying start.

Different types of bikes have different riding positions to suit their purpose. Road racing bikes will put you in a lower position to improve aerodynamics, whereas town bikes will seat you more upright for better comfort. Whatever type of bike you choose there are some general principles which always apply.

When you ride a bike you should be able to:

  • Reach the handlebars and brake levers without stretching

  • Pedal with a small angle in your knee at the bottom of the stroke

  • Stand over the top tube with approximately 5 centimetres of clearance

Hybrid Bikes

Rider
(feet & inches)
Rider
(cm)
Frame Size
(inches)
Frame Size
(cm)
Frame Size
4’10” – 5’2″ 148cm – 158cm 13″ – 14″ 33 – 37cm X Small
5’2″” – 5’6″” 158cm – 168cm 15″ – 16″ 38 – 42cm Small
5’6″ – 5′ 10″ 168cm – 178cm 17″ – 18″ 43 – 47cm Medium
5’10” – 6’1″ 178cm – 185cm 19″ – 20″ 48 – 52cm Large
6’1″ – 6’4″ 185cm – 193cm 21″ – 22″ 53 – 57cm X-Large
6’4″ – 6’6″ 193cm – 198cm 23″ – 24″ 58 – 61cm XX-Large

Mountain Bikes

Rider
(feet & inches)
Rider
(cm)
Frame Size
(inches)
Frame Size
(cm)
Frame Size
4’10” – 5’2″ 148cm – 158cm 13″ – 14″ 33 – 37cm X Small
5’2″” – 5’6″” 158cm – 168cm 15″ – 16″ 38 – 42cm Small
5’6″ – 5′ 10″ 168cm – 178cm 17″ – 18″ 43 – 47cm Medium
5’10” – 6’1″ 178cm – 185cm 19″ – 20″ 48 – 52cm Large
6’1″ – 6’4″ 185cm – 193cm 21″ – 22″ 53 – 57cm X-Large
6’4″ – 6’6″ 193cm – 198cm 23″ – 24″ 58 – 61cm XX-Large

Road Bikes

Rider
(feet & inches)
Rider
(cm)
Frame Size
(inches)
Frame Size
(cm)
Frame Size
4’10” – 5’0″ 148cm – 152cm 18″ – 19″ 47 – 48cm XX-Small
5’0″” – 5’3″” 152cm – 160cm 19″ – 20″ 49 – 50cm X-Small
5’3″ – 5′ 6″ 160cm – 178cm 20″ – 21″ 51 – 53cm Small
5’6″ – 5’9″ 168cm – 175cm 21″ – 22″ 54 – 55cm Medium
5’9″ – 6’0″ 175cm – 183cm 22″ – 23″ 56 – 58cm Large
6’0″ – 6’3″ 183cm – 191cm 23″ – 24″ 58 – 60cm X-Large
6’0″ – 6’6″ 191cm – 198cm  24″ – 25″ 61 – 63cm XX-Large

Childrens Bikes

Your child’s bike should be a perfect fit, so please don’t make the mistake of assuming they’ll grow into a slightly larger bicycle. It’s dangerous! Riding a bike that’s too large may cause steering problems, make braking difficult, or prevent them reaching the ground safely when stopping.

Unlike adult bikes, children’s bikes are specified by wheel diameter. Bikes range from 12-inch bikes for very young kids, to 24-inch bikes for kids approaching 12 years, or whose height approaches 5 ft. After this, kids will move on to adult bikes with smaller frames, smaller wheels, and shorter seat tubes.

 

Rider
(feet & inches)
Rider
(cm)
Inside Leg
(cm)
Age Range
Suggested
Wheel
(inches)
Up to 3″ Up to 90cm Under 40cm Under 2 years Balance Bike
3′ – 3’5″ 90cm – 105cm 40cm 2 – 4 years 12″
3’5″ – 3’9″ 105cm – 118cm 46cm 4 – 7 years 14-16″
3’9″ – 4’5″ 135cm 53cm 53cm 7 – 10 years 18-20″
4’5″ – 5′ 135cm – 150cm 62cm 10 – 13 years 24″