Bike Size Calculator
A 5'9" (175 cm) rider typically fits a 53-55 cm road frame, a size M mountain bike (17-18 in), or a size M hybrid (18-19 in). This bike size calculator recommends a frame size range from your height and the type of bike you ride. Enter your height, choose road, mountain, or hybrid, and calculate to see a suggested size band.
Quick answer
Frame size is matched to a height band, not an exact number.
What this tells you
- •Frame size is matched to a height band, not an exact number.
- •Road bikes are sized in centimeters, mountain and hybrid bikes in inches.
- •The same height can map to a different label depending on bike type.
- •This is a starting point, not a substitute for a professional bike fit.
How to Use
- 1Enter your height and choose centimeters or inches.
- 2Select the type of bike: road, mountain, or hybrid.
- 3Calculate to see the recommended frame size range and size label.
- 4Test ride bikes near that range, since brands vary slightly.
How It Works
Formula
Height is converted to centimeters, then matched to a height band.
Each band maps to a frame size range per bike type.
Example: 175 cm falls in the 168-178 cm band, giving 53-55 cm (road) or 17-18 in (mountain).The calculator converts your height to centimeters if needed, then looks up the height band that contains it. Each band carries a frame size range for road bikes in centimeters and for mountain and hybrid bikes in inches, based on commonly published retailer sizing charts. The result is a range because rider proportions, riding style, and brand geometry all shift the ideal size within that band.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Road bike example
A height of 175 cm falls in the 168-178 cm band, which maps to a 53-55 cm road frame.
Mountain bike example in inches
70 inches converts to 177.8 cm. That stays within the 168-178 cm band, so the calculator returns a 17-18 in M mountain frame.
Hybrid bike from 66 inches
Multiplying 66 by 2.54 gives 167.64 cm, displayed as 167.6 cm. The unrounded value falls in the 157-168 cm band and returns hybrid size S.
Exact band boundary
The comparison includes the band maximum. Exactly 157 cm stays in XS, while 157.1 cm moves into the next band and returns S.
Tall road rider
A height above 193 cm and no more than the supported 220 cm maximum uses the final chart band, giving the XXL road range.
Bike Frame Size by Height
General frame size ranges by height band and bike type, based on commonly published retailer sizing charts.
| Height | Road frame | Mountain frame | Hybrid frame |
|---|---|---|---|
| Up to 5'2" (up to 157 cm) | 47-49 cm (XS) | 13-14 in (XS) | 14-15 in (XS) |
| 5'2"-5'6" (157-168 cm) | 50-52 cm (S) | 15-16 in (S) | 16-17 in (S) |
| 5'6"-5'10" (168-178 cm) | 53-55 cm (M) | 17-18 in (M) | 18-19 in (M) |
| 5'10"-6'1" (178-185 cm) | 56-58 cm (L) | 19-20 in (L) | 20-21 in (L) |
| 6'1"-6'4" (185-193 cm) | 58-60 cm (XL) | 21-22 in (XL) | 22-23 in (XL) |
| 6'4" and up (193 cm and up) | 61-63 cm (XXL) | 23-24 in (XXL) | 24-25 in (XXL) |
These bands are general estimates drawn from widely published bike retailer sizing charts. Individual brands publish their own charts that can differ by a size in either direction.
Why the chart result may not match the best fit
The calculator multiplies inch input by 2.54 and rejects converted heights below 120 cm or above 220 cm. It selects the first band whose maximum includes the rider's unrounded converted height. This makes upper boundaries inclusive. Converted height displays to 1 decimal place after the band has been selected.
Frame labels are not universal measurements. One brand's M can have a different reach, stack, seat-tube angle, and standover height from another brand's M. Even nominal centimeter or inch sizes may refer to different tube measurement methods. Check the geometry table for the exact model and year.
Height cannot describe body proportions. Two riders at 175 cm may have different inseams and torso lengths. The rider with a longer inseam may need different standover clearance or saddle adjustment, while the rider with a longer torso may respond differently to reach. This tool has no inseam input and cannot resolve that difference.
Bike purpose changes fit preferences. A relaxed commuter position, an aggressive road position, and a trail-focused mountain setup place the rider differently. Handlebar shape, stem length, saddle position, crank length, suspension sag, and shoe or pedal system can affect final position without changing the listed frame size.
A test ride should include safe control of brakes and steering, comfortable mounting and dismounting, and enough adjustment range for saddle and cockpit. Stop if the setup causes pain, numbness, poor control, or unsafe standover. A qualified fitter can assess close size decisions, adaptive needs, and persistent discomfort.
Common mistakes
- Using a road bike sizing chart to size a mountain or hybrid bike
- Ignoring inseam, arm length, and riding style, which shift the ideal size within a band
- Buying the top of a size range for a taller-looking bike instead of testing fit
- Assuming letter sizes are identical across brands and model years
- Ignoring the model's reach, stack, standover clearance, and adjustment range
- Treating height as a substitute for inseam and torso measurements
- Continuing to ride through pain, numbness, or poor control instead of checking the setup
Embed this calculator on your site
Drop this single line where you want the calculator to appear. It is responsive, mobile-friendly, resizes automatically, and is free to use with attribution.
<script src="https://calctide.com/embed.js" data-tool="bike-size-calculator" async></script>Preview the embed at /embed/bike-size-calculator/.