Hardtail mountain bike on trail

Mountain Bike Size Guide

Choose the right size mountain bike with our MTB bike size guide. An MTB with a good fit will be more comfortable and easier to handle, as well as enabling you to ride more efficiently.

What size Mountain bike do I need?

Below you'll find our typical mountain bike sizing chart. Click on the frame size you want to see the mountain bike models that are right for you.

Height (feet & inches)

Height (cm)

Frame Size (inches)

Frame Size (cm)

General Sizing

4’8” – 5’1”

143 – 155cm




5’1” – 5’4”

155 – 163cm




5’4” – 5’7”

163 – 170cm




5’7” – 5’10”

170 – 178cm




5’10” – 6’0”

178 – 183cm




6’0” – 6’3”

183 – 191cm




6’3” – 6’5”

191 – 196cm




6’5” – 6’9”

196 – 205cm




What size MTB should I choose if I am between sizes?

Sometimes bike size charts will recommend two different sizing options. This means that both the larger and smaller sizes recommended will both be suitable. It is a personal choice which size to go for, but most mountain bikers tend to opt for the larger size. So you don’t feel too stretched, you can (depending on the model) fit a shorter stem to improve the fit of a larger bike without adversely affecting the handling. This is the opposite to a road bike where it is better to lengthen the stem rather than shorten it.

Kona Mountain Bike front end

How are mountain bikes sized?

Mountain bikes are either sized in inches or with a general size like small or medium. MTB's are sized by the frame and this is traditionally based on the length of the seat tube, measured from the centre of the front chain ring to the top of the seat tube. 

However, mountain bike frames don’t always follow a classical design so the measurement may be based on a virtual seat tube measurement. Sizes do vary slightly between manufacturers. For Example: Specialized offer some of their bikes in sizes S1 - S5. This gives plenty of options to size up or size down depending on riding style as well as rider height.

Note: For model specific sizing please check the sizing tab on the product page.

Measuring MTB for sizing

Does wheel size make a difference

Predominantly there are three wheel sizes used on mountain bikes; 26", 27.5" and 29" but some others do exist like 27.5+ and becoming more prevalent 'Mullet MTBs' (27.5″ rear & 29″ front).

The size of wheel you pick will alter your riding position & riding style - checkout below which wheel size will suit you best.

26" wheels

26 inch MTB

This is the traditional mountain bike wheel size but most MTBs now feature larger wheels. 26” wheels are still a good option for junior riders and smaller adults who will find them more manageable than larger hoops. Most dirt jump MTBs still roll on 26” wheels.

27.5" (650b) wheels

Shop 27.5

This is now the most common wheel size on all mountain bikes from trail bikes to downhill steeds. 27.5” wheels offer the ideal balance between the nimble handling characteristics and rapid rolling performance. Some manufacturers offer 27.5” wheels on smaller sized models with 29” wheels for the larger frame sizes.

27.5"+ (6Fattie) wheels

27.5 inch or 6Fattie MTB wheel size

With 2.8” and 3.0” tyres on a 27.5” rim these tyres have a similar overall diameter to 29” wheels and are often compatible with 29er MTBs that feature BOOST axle spacing on the fork and back wheel. Offering more grip and more float (cushioning) this wheel size is ideal for hardtails although the extra weight will make them slower to accelerate.

29" wheels

29 MTB Bikes

29ers are becoming increasingly popular, especially with cross country, enduro and downhill racers. While slower to accelerate, these larger hoops carry speed much better over rough terrain so tend to be faster and offer more grip due to the larger contact patch of the tyre on the ground. They are less nimble than 27.5” wheels and some smaller riders will find them a bit of a handful in technical terrain.

Frequently Asked Questions

What size mountain bike is right for me?

The best size mountain bike for you will depend on your height. See our mountain bike size chart to see which size is best for you. Before you buy be sure to check the size chart for the specific model that you are interested in.

What height is a 27.5 bike for?

Mountain bikes with 27.5 inch wheels are suitable for adults of all heights. These bikes offer nimbler handling than 29 inch wheeled MTBs. Sometimes they are only available in smaller frame sizes and some shorter riders prefer the fit of a bike with 27.5 inch wheels.

Is it better to get a bigger or smaller mountain bike frame?

It’s the length or reach of a bike affects its handling. Longer bikes are more stable which is good for steep tracks and riding fast on rough terrain. Shorter bikes are nimbler which is good for tight turns. If you are in between sizes, then you can choose a size that suits your riding style best.

Should my feet touch the ground on a mountain bike?

On a mountain bike it’s good idea if both your feet can touch the ground when you are standing astride the bike. Most modern mountain bikes have low top tubes, so this is easy to do. Your feet don’t need to touch the ground when you’re sitting in the saddle.

What size mountain bike should I get if I'm 5 ft 11 inch?

A large size or 19 inch MTB is generally ideal for someone who is 5 ft 11 inch tall. See our MTB size chart for more and remember to check the model specific size chart before you buy.

What does a 26 inch bike mean?

A 26 inch bike is a bike with 26 inch inch wheels. This wheel size was common on mountain bikes but is now only found on smaller frame size MTBs or jump bikes.

Should I get a 27.5 or 29 mountain bike?

Wheel size is a personal choice. 27.5 inch wheel mountain bikes offer more nimble handing while 29ers are faster rolling. Shorter riders often prefer the fit of a 27.5 inch wheel MTB while taller riders tend prefer 29” wheels.

How do you size a trail bike?

Trail bikes are sized in the same way as other mountain bikes. The best way to find the right size trail bike is to check the size chart for the bike that you are interested in or see our MTB size chart.