Think of a bike size chart as a clothing size. It's intended to be used as a guide, helping you to decide the correct size your body.
Ever bought clothing without checking the size first? You get it home and can't wait to wear it. But your heads too big and you can't get it on past your ears.
The same thing applies to bicycles. But no worries. Just check a chart first, and you'll be sorted.
The Measurements You Need
There are three simple measurements that you’ll need to help you choose the correct size bike for your body shape. Height, inside leg and your reach.
Inside Leg
Your inside leg measurement will determine your stand over height. Stand over height is the clearance between the top tube of the bike and your crotch when stood just in front of the saddle.
I recommend a clearance of two inches, minimum. Two inches will allow you to hop off the bike quickly and protect any valuables from getting knocked in the process.
- To calculate the measurement, take off your shoes and stand with your legs 15-20cm apart.
- Place a book between your legs and slide it up a wall to meet the crotch, as if you're sat on the saddle.
- Mark with a pencil where the top of the book touches the wall.
- Measure from that mark straight down to the floor.
Your Reach
It’s possible that your height and inside leg measurements will put you in-between two size categories. In this case, your upper body should be the deciding factor in selecting the best sized bike for you.
This is because your upper body dimensions determine your reach and how far you have to stretch along the top tube of your bike.
To work out if you have a long or short reach you’ll need to establish your ‘Ape Index’ (arm space minus your height).
- If you have a positive ape index (your arm span is greater than your height), then I’d suggest you go for the larger of the two bikes sizes
- If you have a negative ape index (your arm span is less than your height), then I’d suggest you go for the smaller of the two bike sizes
Example: Arm span (160cm) minus Height (155cm) = Ape Index (5cm)
In this example, the subject has a positive ape index and would probably be more suited to the larger of the two bikes.
Once you've picked your frame size don't forget to fit your bike properly. The video below by the Global Cycling Network gives a great explanation on how to do this.
The Difference Between Men And Women Bikes
On average, a woman has longer legs and shorter torsos than men of the same height. So, female specific bikes have a shorter top tube, narrower handlebars, and female specific saddles.
As a rough rule, if you're shorter than about 165cm, or have felt like you were too stretched out on men's/unisex bikes before, then you may be more suited to a female specific bike.
How Do You Choose Bikes Sizes For Kids?
Children's bicycles are measured differently to adults. They're usually categorized by age groups and wheel sizes.
A Kids Bike Size Guide
- The age ranges to size the bike for your child are just a guide. There’s always that one child who's over 6ft and sporting better stubble then his dad.
If this is your son then you might have to pick the next age group up. - As kids develop quickly it’s common to look for a bike that the child can ‘grow into’.
Try to avoid this as it could scare them off. Riding an oversized bike is uncomfortable, and could result in them not riding a bike at all. - Height and inside leg measurements are still an essential factor when sizing so keep this in mind when choosing a bike
Bike Sizing Table
For future reference here's a list of charts. Make sure to select the correct bike category, find your size and get riding.
Road bike sizing chart - Standard | ||
|---|---|---|
Height | Inside Leg | Frame Size |
5'1" - 5'3" | 27" - 29" | 48cm |
5'3" - 5'5" | 28" - 30" | 50cm |
5'5" - 5'7" | 29" - 31" | 52cm |
5'7" - 5'9" | 30" - 32" | 54cm |
5'9" - 5'11" | 31" - 33" | 56cm |
5'11" - 6'2" | 32" - 34" | 58cm |
6'1" - 6'3" | 33" - 35" | 60cm |
6'3" - 6'5" | 34" - 36" | 62cm |
Woman's road bike | ||
|---|---|---|
Height | Inside Leg | Frame Size |
5'0" - 5'2" | 26" - 28" | 2XS |
5'2" - 5'4" | 27" - 29" | XS |
5'4" - 5'6" | 28" - 30" | S |
5'6" - 5'8" | 29" - 31" | M |
5'7" - 5'10" | 30" - 32" | L |
MTB - Off road (hardtail) | MTB - Off road (full suspension) | ||||
|---|---|---|---|---|---|
Height | Inside Leg | Frame Size | Height | Inside Leg | Frame Size |
4'10" - 5'0" | 26" - 28" | 13" | 5'4" - 5'7" | 28" - 30" | 14", 15" |
5'0" - 5'3" | 27" - 29" | 14", 15" | 5'8" - 5'9" | 29" - 31" | 16", 17", 18" |
5'4" - 5'7" | 28" - 30" | 16", 17" | 5'10" + | 30" - 32" | 19", 20", 21" |
5'8" - 5'9" | 29" - 31" | 18", 19" | |||
5'10" - 5'11" | 30" - 32" | 20" | |||
6'0" - 6'2" | 32" - 34" | 21" | |||
6'2" - 6'4" | 33" - 35" | 22" | |||
Hybrid - Leisure/Comfort | Hybrid - Sport/Commuter | ||||
|---|---|---|---|---|---|
Height | Inside Leg | Frame Size | Height | Inside Leg | Frame Size |
4'10" + | 26" - 28" | 13", 14" | 4'10" + | 26" - 28" | 13", 14" |
5'0" + | 27" - 29" | 15" | 5'0" + | 27" - 29" | 15" |
5'2" + | 27" - 29" | 16" | 5'2" + | 27" - 29" | 16" |
5'4" + | 28" - 30" | 17" | 5'4" + | 28" - 30" | 17" |
5'6" + | 28" - 30" | 18" | 5'6" + | 28" - 30" | 18" |
5'8" + | 29" - 31" | 19" | 5'8" + | 29" - 31" | 19" |
5'10" + | 30" - 32" | 21" | 5'10" + | 30" - 32" | 21" |
6'0" + | 32" - 34" | 22" | 6'0" + | 32" - 34" | 22" |
kids | ||
|---|---|---|
Height | Inside Leg | Wheel Size |
2 - 4 yrs | 30cm | 12" or beginner bikes |
2 - 5 yrs | 30cm | 12" |
3 - 5 yrs | 36cm | 16" |
5 - 7 yrs | 41cm | 16" |
7 - 9 yrs | 51cm | 20" |
9 - 11yrs | 61cm | 24" |
11 and up | 66cm | 26" |
