What Bike Frame Size Do I Need?

What Bike Frame Size Do I Need?

Whether road biking, mountain biking or commuting by bike; how your bike fits really matters.  A proper bike frame size will ensure you're riding position isn't straining your body in any way; as well as, ensure optimal performance out of each pedal. There are adjustments you can make to the seat or handle bars to better fit the uniqueness of your body, which we'll address later, but the foundation to getting the most power out of your pedaling while maintaining a safe and comfortable position, all boils down to the bike frame size.

Finding what bike frame size you need is easy.

1. Know What the Bike Frame Is

The bike frame is the unmovable part of the bike that all other components of the bike attach to.

The anatomy of a bike frame looks like this:

What bike frame size do I need?

2. Know What Style of Bike You Want 

The sizing  of your frame is a little different depending on if you want a road, mountain, hybrid, or cyclocross bike.  This is because the frames are a little different.

Road Bike Frame Size Sizing


3. Know Your Height

In this case, size matters.  Measure yourself with a tape measure head to toe.  This isn't a driver's license...don't lie.

4. Refer To The Sizing Chart 

Based on your height and bike style, use the charts below to find the suggested bike frame size.  The frame size measurement is referring to the length of the seat tube.


Note: some cyclocross riders like to size down to compensate for the frame's higher bottom bracket and lower saddle position.

Rider Height Suggested Frame Size (cm) Size
4'10" - 5'0" 47cm - 48cm XXS
5'0" - 5'3" 49cm - 50cm XS
5'3" - 5'6" 54cm - 55cm S
5'9" - 6'0" 56cm - 58cm M
6'0" - 6'3" 58cm - 63cm L
6'3" - 6'6" 61cm - 63cm XL



There are women-specific bike frames to accommodate a shorter reach and narrower shoulders, typically the top tube is angled for an easier step-over.  These charts are based on women road bike frames; however, there is no reason a woman can't ride a unisex or male bike - it's all preference!

Rider Height Suggested Frame Size (cm) Size
4'10" - 5'1" 44cm - 46cm XXS
5'1" - 5'3" 47cm - 49cm XS
5'3" - 5'5" 50cm - 52cm S
5'5" - 5'8" 53cm - 55cm M
5'8" - 5'10" 56cm - 57cm L


Rider Height Suggested Frame Size (cm) Size
4'10" - 5'2" 13" - 14" XS
5'2" - 5'6" 15" - 16" S
5'6" - 5'10" 17" - 18" M
5'10" - 6'1" 19" - 20" L
6'1" - 6'4" 21" - 22" XL
6'4" - 6'6" 23" -24" XXL

5. Identify the Size of the Bike Frame

Now that you know approximately what size bike you're looking for, you need to know where to find the the size of the bike frame.

To do this, you can typically look at the seat tube, just below the top tube, to find a sticker that states the size of the frame.  Again, the measurement signifies the length of the seat tube.  If you are unable to find a sticker or decal providing the frame size, you can get a tape measure and measure the seat tube.  To measure the seat tube, measure from the very end of the tube on both ends of the bike, do not include the stem included with the seat.

6. Straddle the Bike

That's right - now that you've found the bike frame in your suggested range, you want to stand over the bike.  Even with charts and suggestions, people have longer legs or torsos then other people their height.  You want to make sure this frame really is a good fit for you in all your unique glory.

Standing over the bike, you want to make sure first and foremost you didn't just rack yourself...that doesn't feel good no matter what gender you are.  You do not want any part of your crotch touching the top tube.  You also don't want too much space.

For a road bike, you want about 1 inch of space between you and the bike. 

Four a mountain bike or hybrid, you want about 2 inches.

If you need to disregard what the chart's say and size up or down to ensure the optimal stand-over clearance - there is no shame!  As well, it does depend on your preference.  

That's it! If you've done the above, you've found the right bike frame size for you. Enjoy! 

zilker pace bike frame size

Next you'll want to fit the bike to you, which will focus on adjusting the following:

  • Saddle height
  • Saddle setback
  • Reach 
  • Drop

More on that to come!

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