What Size Mountain Bike Do I Need? How to Find the Right Fit for You


Whether you’ve never ridden before or simply need a new bike, you might be wondering, “what size mountain bike do I need?” It’s a good question, and getting it right can make a huge difference in your experience. But a lot goes into finding the right sized mountain bike for you.




image by pexels

If you are shopping for a bike, you should ask yourself the question, “what size mountain bike do I need?” However, you should also consider your biking abilities as well as some other factors.

Riding an ill-fitting mountain bike may not be the end of the world. Sure, it might be a little tight or hard to reach the pedals. On the other hand, the more you ride that bike, the more you’ll wish you chose the correct size.

Choosing the right size mountain bike is an art. While there are tons of size charts you can find, none of them are perfect.

Many things can affect how a bike feels. Of course, your height can make a big difference, so that’s an excellent place to start.


You may want to know, “what size mountain bike do I need as a short person?” It should come as no surprise that you probably won’t be able to ride the largest mountain bikes comfortably.

A bike with 26-inch wheels is a good place to start if you’re on the shorter side. This can be a good fit for adults who are a little shorter than average.

Merax 26″ Mountain Bicycle with Suspension Fork 24-Speed…

  • Front suspension forks design…
  • Fitted Shimano 24-speed…
  • Dual disc brakes provide…
  • Designed to be the most fully…
  • Weight Capacity: 330 lbs,1…

If you’re short, you need a bike where you can reach the pedals and potentially adjust the height of the saddle.

That’s because not only should your feet reach the pedal, but they should come close to the ground. That way, you can start and stop more easily.


You know you’re not super short. So, you might be thinking, “what size mountain bike do I need if I’m an average height?”

Depending on your exact height, you may fit perfectly on bikes with 26-inch wheels. But if you’re firmly in the “average” height category, you may feel squished.

In that case, try a bike with 27.5-inch wheels. The slightly bigger wheels will set you a little more off the ground. That way, you will have a bit more height, which is nice if y
ou have long legs.

Diamondback Bicycles Hook 27.5 Wheel Mountain Bike, Red,…

  • Reliable, hand-built aluminum…
  • SR Sun tour XCM 120mm travel…
  • SRAM single ring 1×8…
  • Durable DB SL-7 Double wall…
  • Powerful Tetra Aries…

But what if you’re slightly taller than average? Sure, the 27.5-inch wheels might be a little small for you. Luckily, there are bigger mountain bikes.


Taller riders will want to know, “what size mountain bike do I need as a tall person?” Of course, there’s no one-size-fits-all bike for taller people.

Like people in general, “tall” people could be anywhere from 5 feet 10 inches to well over 6 feet tall. Still, if you find that 27.5-inch wheeled bikes are too small for you, you have another option.

That’s where bikes with 29-inch wheels come into play. These wheels are even bigger than those of “average” sized bikes. They can lift you a bit more off the ground and leave room for long legs.

Schwinn Traxion Full Dual-Suspension Mountain Bike,…

  • Schwinn aluminum dual…
  • 24 speed Shimano EZ Fire…
  • Front and rear mechanical disc…
  • Extra wide double wall alloy…
  • Durable Schwinn alloy cranks…

Now, if these bikes still aren’t big enough, see if you can adjust the height of the saddle. Just like how shorter people may need to lower it, taller people may need to raise it for a better fit.


feet on pedal

image by pexels

Unfortunately, no mountain bike will be the perfect size. We can try to answer the question of “what size mountain bike do I need?”

However, many things can cause our suggestions to be incorrect. Perhaps you’re shorter than average but have long legs. You may not need a super small bike.

On the other hand, a tall person who doesn’t have long legs might not be comfortable on a large bike.

A mountain bike size guide is meant to guide you, but only you can figure out your answer to, “what size mountain bike do I need?”

The most important thing is that you choose a comfortable bike. Yes, even if that means it doesn’t perfectly follow a size chart.


man biking

image by pixabay

Of course, you can’t entirely rely on a mountain bike size chart. However, part of answering, “what size mountain bike do I need?” involves figuring out what you need to feel comfortable and safe on your mountain bike.

Suggested sizes are an excellent place to start, especially if you’ve never ridden a mountain bike before.

But for some of us, the suggested size might not be correct. Often, these sizes primarily consider your height. They don’t always factor in body proportions or other considerations.

So, what else should you consider to better answer the question, “what size mountain bike do I need?”

All about comfort

The biggest thing with any bike, mountain bikes included, is comfort. If your bike is uncomfortable, you won’t want to ride it. You’ll have wasted money on a bike that you never use.

Think about it; if your car’s seats were uncomfortable, would you want to drive it? Probably not. So the same is probably true of a mountain bike. Of course, comfort can mean different things to different people. Some of us may want a softer seat, while others prefer something harder.

Maybe you want to reach the ground for easier stops, while another rider doesn’t care as much.

Think about how you want to feel during every moment of a ride. Then, you can take those ideas and test them on different mountain bikes.

Measure yourself

If you don’t already know your height, try to measure yourself. Grab a friend and a tape measure to see how tall you are.

You can also call your doctor’s office to see if they have any recent height records on file. While your height isn’t everything, it can be a great place to start when answering, “what size mountain bike do I need?”

Don’t stop at your height, though. You should also measure your inseam since that can give you a better picture of your leg length. Similarly, measuring your arms can help when deciding on where your handlebars need to be.

If you take these measurements before you start bike shopping, the process can go more quickly. You can whip out your measurements and give them to the sales associate who can help you find the right size bike.

Also, don’t forget that measuring for a mountain bike isn’t the same as measuring for a city bike. Mountain bike frames tend to be smaller than those of city bikes.

While you may know the perfect size city bike, it won’t always translate. So don’t underestimate starting from scratch.

The frame

Speaking of mountain bike frames, your inseam is a good measurement to know when determining the right frame size. You want to get the measurement in centimeters, but if it’s in inches, you can always convert it.

Before you can find the answer to “what size mountain bike do I need?” you have to find the city bike size. To do this, take your inseam in centimeters, and multiply it by 0.65.

Now to find the frame size you need for a mountain bike, subtract 10 centimeters. You can then convert that measurement into inches to find the perfect frame.


Next, you want to consider the saddle height of your bicycle. Assuming you plan to sit at least some of the time while riding, you want a saddle that still allows you to reach the pedals.

To get an idea of how high your saddle should be, stand over a bike with one leg hanging free. Both of your hips should face forward. You should be able to reach the pedal with your hanging leg, and your leg should be somewhat straight. However, you do want some bend so that you don’t have to reach too much.

If you want to get a specific height measurement, take your inseam, and multiply it by 0.883. That should give you your ideal saddle height.


Another thing to consider is the tube height. While mountain bikes usually have the same frame measurements, tube height can vary.

Two bikes with the same frame size might have different tube lengths. On the other hand, two bikes with the same tube length might have different frame sizes.

Men are lucky in this area since bikes are usually built to fit men’s proportions. However, women tend to have longer legs than men of the same height. That doesn’t mean women can’t ride mountain bikes. But it can make it harder for women to find the right size.


You may wonder what handlebars have to do with the question, “what size bike do I need?” However, handlebars can play a role in aerodynamics and speed.

If you want to go fast, you need handlebars that are lower and more toward the front. That way, you can lower your center of gravity to take advantage of aerodynamics and increase your speed.

On the other hand, higher handlebars that are farther back tend to be more comfortable. So consider what you need or want in a bike when deciding on the best location for your handlebars.


biker/mountain bike

image by pexels

It may seem like you can choose any bike and be fine. But it’s more complicated than that. A lot goes into finding the correct answer to “what size mountain bike do I need?

Things like your overall height are a great starting point. However, your inseam and comfort preferences can further affect which mountain bike is best for you.

Have you found the perfect mountain bike? Leave your thoughts and shopping tips in the comments!

The Out sider

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