Bicycle sizing is a delicate matter. Manufacturers make frames of different sizes, and choosing a bike is more or less as choosing a pair of cycling shorts. Your height and gender matter, as well as your body type and a series of other factors.
But how to choose the right bike for you? There are multiple methods but we decided to focus on the two most popular. Here they are.
Calculate The Bike Size Based On Your Height
The traditional method of choosing the right bike size is by calculating the size you need based on your height. Also known as the leg inseam method, this bike sizing technique involves a bit of math, as you’ll have to transform all measures from inches to centimeters and back to inches.
Apart from this, the method is straightforward. Just take off your shoes and stand with your legs at about 6-8 inches apart. Measure your leg inseam, which is the height from the ground to the crotch. Now, grab a calculator or use your math skills to calculate the frame size.
The formula uses different numbers for different bike frames. Below, the formulas to calculate the size of the most popular types of bikes on the market.
Mountain Bike Sizing
Leg inseam height in centimeters x 0.66 = ideal frame size. For example, if your leg inseam is 76cm you’ll have to calculate 76×0.66=50,16cm. Round this figure to 50cm, which translated into inches means you’ll need a 20-inch bike.
Road Bike Sizing
In this case, the formula changes from leg inseam height in centimeters x 0.66 to the leg inseam height in centimeters x 0.70. Following on the example above, this means you’ll need a 21-inch road bike.
If you’re a commuter, just multiply your leg inseam height in cm by 0.685 to get the right biking size. Alternatively, you can use a size chart that indicates the right size in inches or in international sizing according to your overall height.
Bike Sizing Chart
The easiest way to determine bicycle sizing is by consulting a sizing chart. Since different styles of bikes have different ideal sizes, here are the bike charts for the most common types of bikes.
Mountain And Urban Bikes
These two models of bikes follow the same sizing rules. In the international system, their size varies from XS to XXL, although these figures can have different meanings for different manufacturers. That’s why it’s always indicated to choose the frame size based on your height.
The corresponding measures are as follows:
- 4’10” to 5’1” tall riders: 14-inch bike frame or XS
- 5’2” to 5’5” tall riders: 15-inch bike frame or S
- 5’6” to 5’9” tall riders: 16-inch bike frame or M
- 5’9” to 6’0” tall riders: 17-inch bike frame or L
- 6’0” to 6’3” tall riders: 18-inch bike frame or XL
- 6’3” to 6’6” tall riders: 19-inch bike frame or XXL
Road bikes are slightly larger than mountain and urban bikes, that’s why they have a different sizing system. Search the right frame size in the table below.
- 4’10” to 5’1” tall riders: 18-inch bike frame or XS
- 5’2” to 5’5” tall riders: 19 to 20-inch bike frame or S
- 5’6” to 5’9” tall riders: 21-inch bike frame or M
- 5’9” to 6’0” tall riders: 22-inch bike frame or L
- 6’0” to 6’3” tall riders: 23-inch bike frame or XL
- 6’3” to 6’6” tall riders: 24-inch bike frame or XXL
Bicycle sizing could be tricky, but I hope these methods can help you find the right bike for you. Our only suggestion is to always measure the size of the frame and match it with your height. Or to use the leg inseam method above.
International sizing is inaccurate. Companies use the XS to XXL measures in a way similar to clothing and the bikes may not come at standard sizes.