Mountain Bike Size Chart: How to Choose the Perfect Size for You

mtb size chart

Purchasing a mountain bike online saves you the hassle of having to visit a brick and mortar store. It can also help you avoid warehouse and inventory costs. However, it can be challenging to pick the correct size if you are browsing online.

Luckily, there are a number of tactics you can use to properly size a bike and find your perfect fit.

Before we get into that, here’s some more information about the anatomy of a mountain bike and how each part should inform your decision:

mtb sizing guide

Frame Sizes

All bikes have a different feel to them, regardless of the similarities between their builds. The process that manufacturers use for sizing bikes often differs. Traditionally, the seat tube length is measured. However, some people measure to the top of the seat tube, while others only measure to the middle of where the seat tube meets the top tube.

A lot of manufacturers use the XS, S, M, L, XL, sizing. The two most important measurements to consider when you are considering frame size is the seat tube length and top tube length.

two boys on mountain bikes

Standover & Seat Tube Length 

The seat tube is supposed to leave you with an adequate standover gap and a usable standover clearance. To measure this, stand as far back as you can while you are still over the bike and make sure there is at least an inch of room from the top tube to your crotch.

If you consider this advice, your frame should have a large adjustment range, which will help you find the right saddle height.

Reach and Top Tube Length

Another important factor to consider is the top tube length. Along with stem length, handlebar positioning, and seat positioning, top tube length is what determines how comfortable and efficient your bike’s body will be.

Most of these components are adjustable, so it’s important to look at the manufacturer size chart of whatever mountain bike you are considering. It’s important not to guess- the more exact you can measure, the more comfortable your bike will be to use.

Here are some other ways to figure out what size bike you should purchase:

Measuring Bike Height

The frame size of the bike you choose depends on your height. If you are taller, you require a bigger frame size. Here is a bike size chart in inches for reference.

Calculating Bike Size

To do this method, first, take off your shoes and stand with your legs shoulder-width apart. Measure the height starting from the ground to your crotch.

Depending on the type of bike you want, the calculation will vary a bit. For mountain bikes, take your leg inseam (cm) and multiply it by 0.66. This equals the frame size that you should get.

For a leg inseam of 76cm, you should purchase a bike with a frame size of 20” or 50cm.

Dealing with Common Frame Problems

If you ignore the advice of our specialized bike size chart and choose the incorrect bike size, you could run into a few different problems.

  • If your frame is too big, you can experience a sore back due to overreaching.
  • If you don’t have enough standover clearance and you are not rested on the seat, the frame will press into your crotch area. You may also notice that it is difficult to control your bike.
  • If your frame is too small, you could end up injuring yourself due to being in a cramped position. You also run the risk of toe overlap problems (where your foot will clip the front wheel).

With a small frame, you have too much standover clearance, which can also cause back problems when you ride for an extended period of time.

Adjusting the Fit

man posing with his mountain bike

Regardless of what the appropriate size for your build is, you have to ensure that you feel comfortable on your mountain bike. A bicycle sizing chart can only tell you so much.

If possible, you should take a few different frame sizes out for a test run. This way, you can assess whether you feel like the model is a good fit before you purchase.

Aside from the frame size, make sure that your bike fits the main contact points (saddle, pedals, handlebars).

Once you’ve decided on the frame size and purchased your mountain bike, don’t hesitate to play with the adjustment features and make alterations as needed. Mountain bikes are meant to be customized to your liking.

Fitting Women’s Mountain Bikes

Women typically have narrower shoulders and longer legs compared to men. There are many women-specific bikes that compensate for these differences in build, and many women’s bike size charts on the web.

These mountain bikes typically have narrower handlebars and shorter frames. Some women like the feel of men’s bikes, but that isn’t always the case. If you are a woman in the market for a mountain bike, check out some models that are made for women to see if you can get a better fit.

Final Thoughts

While there are a number of features you’ll want to consider when you begin your search for the perfect mountain bike, frame size is arguably the most important factor. The frame size and height depend on your build and height. If you are tall, you will most likely require a larger frame.

Every bike manufacturer is different, so it’s important to check their sizing guides so you can be sure that you’ve made the right choice. We hope that our guide helped you understand some of the variables that you must consider when picking a mountain bike.

If you are in the market for a different type of bike, find a trek bike size chart or another specialized bike size chart online for a point of reference.

Check out some of our other reviews or click here to purchase some of our mountain bike picks. We know which bikes are the best for all types of riders. We carry many top-selling brands, like Giant, Diamondback, Schwinn, and Fuji.

Try out our size chart with any of these 2019 models today. It’s the best way to feel confident in your brand new bike before you buy!