How to know what size bike to get?

Looking to shop for a bicycle online? Look no further! If you haven’t bought a bike online, you must be worried whether or not you will get what you want. If your not, then you should be. Purchasing a bicycle like any other part of online shopping has its risks.

  • Is it the right size?
  • Will I be comfortable riding it?
  • Will it help me win a group race?

Let’s figure out the answers to these questions ( and don’t worry, going to a salesperson is not one of them).

The answers.

Multiple ways can help determine what bike size you need. Most of the methods I picked generally cut across all types of bike models. There are others that detail for specific bike models.

If you are not the average bike-head here are a few definitions that should make you not feel out of place before we start sizing.

Top-tube – It is the horizontal bar connecting the seat to the handle.

Seat-tube – This is the upright bar between your seat (top-tube) and pedals. It supports the crankshaft ( The circular disc that rotates when you pedal) at its end.

Head-tube – It’s also an upright bar situated at the front of your bike joining the front wheel and the handlebar stem.

Method 1: Calculating bike size.

There are a variety of methods to calculate what size bike fits you. Here’s a pretty simple one to try.

To find your seat tube height follow these steps

Step one: measure your inseam.

Start by taking your inside leg (inseam) measurement.

Next measure the distance from the inside of your foot to the crotch area ( where your pubic bone meets the hip).

Record that height in centimeters on a piece of paper.

Step two- calculate our seat tube height.

Take the height (from step one) and multiply it by 0.67 to determine your appropriate seat tube height.

Although the seat tube of some models is not measured from the top to the crankshaft in some bike models, this Calculation should still work in this case.

2. Now, to determine your frame size.

Step one – carry down your inseam measurements. ( Unless you wish to repeat measuring)

Step two – Next, subtract 4 (or 5) inches from your inseam to get approximate of your appropriate top tube length.

If you notice that the frame size for your particular model is given by seat tube length multiply your inside height measurement by 0.185.


If your thinking of getting a specialty bike use 0.67 instead of .62 to calculate your inseam.

Method 2: Bike height chart.

This is an easy method used to find your bicycle size. The concept is pretty basic, and it involves cross-referencing your height to an appropriate frame range. Explaining this idea makes it seem a lot more complex than it is. Have a look, and you will understand what I mean÷

The bicycle height chart.

4’11” – 5’3″ = 13 – 15 inches

5’3″ – 5’7″ = 15 – 17 inches

5’7″ – 5’11” = 17 – 19 inches

6’0″ – 6’2″ = 19 – 21 inches

6’2″ – 6’4″ = 21 – 23 inches

6’4″ and taller = 23+ inches

Make sure you got the idea. Find your height on the left and check the corresponding bike frame in inches. Pretty easy huh?

Method 3: Trial and error.

With all the math and measurements involved in finding a suitable bike, there is always room for error. A correctly sized bike can turn out to be uncomfortable when you get on it. Finding a bike design that suits you sometimes requires more than calculating the frame size. There’s no denying the fact that calculating desired frame size gives you a headstart in finding a comfortable bike it does not replace the feeling of trying out the bike first-hand. Negotiate to purchase bikes that you can return if you don’t like it feels on the road.

Smart bike buying.

A bicycle is not a small investment. Always get as much information about the product you want to purchase. The rewarding part of reading long articles like this one is that you get smart insights on shopping at the end. Here are a few:

  • If you are just starting on biking, start small and gradually upgrade. What this means is that for a startup Mountain biker, begin with gentle trails that do not need advanced suspension.
  • If you only want to ride occasionally, look for a cheaper cruiser bike.
  • Always look at the frame of a bike before anything. The frame is the most expensive part of a bike.
  • Check out our best mountain bike and best fat tire bike.


Your comfort comes first. Never ride a bike you feel uncomfortable on. A quick talking salesman might try to persuade you to purchase such a bike. Don’t! It’s not worth it.