One of the most frequently asked questions by cyclists looking for a new bike is, “What size bike do I need?” or “Which bike size is right for me?”
Determining the correct bike size might seem complex and time-consuming to many new cyclists. But from my experience, it doesn’t have to be once you understand the basics.
I’ll explain the process to help you quickly determine the ideal bike size that fits your body comfortably and riding style.
In the following sections, I’ll cover the five common methods to determine the right bike size for yourself, ranked from the easiest to hardest.
Method 1. Using generic bike size charts
Generic bike sizing charts are the easiest and fastest way to find the right bike size based on height. While generic bike sizing charts are a starting point, they should be used with other methods to fine-tune the bike size.
Road bike size chart by height
| Your height | Bike size | Bike size (cm) |
|---|---|---|
| 4’10″ to 5’2″ 147 to 157 cm | XXS | 47 to 48 cm |
| 5’2″ to 5’6″ 157 to 168 cm | XS | 49 to 50 cm |
| 5’3″ to 5’6″ 160 to 168 cm | S | 51 to 53 cm |
| 5’6″ to 5’9″ 168 to 175 cm | M | 54 to 55 cm |
| 5’9″ to 6’0″ 175 to 183 cm | L | 56 to 58 cm |
| 6’0″ to 6’3″ 183 to 191 cm | XL | 58 to 60 cm |
| 6’3″ to 6’6″ 191 to 198 cm | XXL | 61 to 63 cm |
Mountain bike size chart by height
| Your height | Bike size | Bike size (inches) |
|---|---|---|
| 4’11″ to 5’3″ 150 to 160 cm | XS | 13″ to 15″ |
| 5’3″ to 5’7″ 160 to 170 cm | S | 15″ to 16″ |
| 5’7″ to 5’11″ 170 to 180 cm | M | 16″ to 17″ |
| 6’0″ to 6’2″ 180 to 188 cm | L | 17″ to 19″ |
| 6’2″ to 6’4″ 188 to 193 cm | XL | 19″ to 21″ |
| Above 6’4″ Above 193 cm | XXL | Above 21″ |
Hybrid bike size chart by height
| Your height | Bike size | Bike size (inches) | Bike size (cm) |
|---|---|---|---|
| 4′ 10″ to 5′ 1″ 147 to 155 cm | XS | 13″ to 14″ | 47 to 49 cm |
| 5′ 1″ to 5′ 5″ 155 to 165 cm | S | 15″ to 16″ | 50 to 52 cm |
| 5′ 5″ to 5′ 9″ 165 to 175 cm | M | 17″ to 18″ | 53 to 54 cm |
| 5′ 9″ to 6′ 0″ 175 to 183 cm | L | 19″ to 20″ | 55 to 57 cm |
| 6′ 0″ to 6′ 3″ 183 to 191 cm | XL | 21″ to 22″ | 58 to 61 cm |
| 6′ 3″ to 6′ 6″ 191 to 198 cm | XXL | 23″ to 25″ | 61 to 63 cm |
Kids bike size chart by height
| Kids height | Kids age | Bike wheel size |
|---|---|---|
| 3’1″ to 3’3″ 90 to 100 cm | 3 to 4 | 12″ |
| 3’3″ to 3’7″ 100 to 110 cm | 4 to 5 | 14″ |
| 3’7″ to 4’0″ 110 to 120 cm | 5 to 8 | 16″ to 18″ |
| 4’0″ to 4’5″ 120 to 135 cm | 7 to 9 | 20″ |
| 4’5″ to 4’9″ 135 to 145 cm | 8 to 11 | 24″ |
Method 2. Using inseam measurement
The inseam measurement is crucial in determining the right bike size, as it accurately reflects your leg length.
A correctly sized bike based on inseam ensures adequate standover height and optimal saddle positioning, enhancing comfort and cycling efficiency.
How to measure your inseam at home
- Find a suitable location. Choose a flat, level surface near a wall for support during the measurement process.
- Dress appropriately. Wear tight-fitting pants or shorts and remove your shoes to ensure accurate measurements.
- Position yourself. Stand with your back against the wall, feet shoulder-width apart, and heels touching the wall.
- Measure your inseam. Place a large book or a similar flat object between your legs, with the spine pressed firmly against your crotch, mimicking the pressure of a bike saddle. Use a measuring tape to measure the distance from the top of the book’s spine to the floor. Record this measurement in centimeters or inches.
Road bike sizing based on inseam
Compare your inseam measurement against the road bike sizes in the table below.
Some bike brands, such as Cannondale, Boardman, and Orbea, don’t offer smaller road bike sizes for cyclists below 5’2″ (158cm).
| Your height | Your inseam | Road bike size (cm) |
|---|---|---|
| 5’0″ to 5’2″ 152 to 158 cm | 28″ to 30″ 71 to 75 cm | 48 |
| 5’2″ to 5’4″ 158 to 163 cm | 29″ to 30″ 74 to 77 cm | 50 |
| 5’4″ to 5’6″ 163 to 168 cm | 30″ to 31″ 76 to 79 cm | 52 |
| 5’6″ to 5’9″ 168 to 174 cm | 31″ to 32″ 78 to 82 cm | 54 |
| 5’9″ to 5’11″ 174 to 180 cm | 32″ to 33″ 81 to 85 cm | 56 |
| 5’11″ to 6’1″ 180 to 185 cm | 33″ to 34″ 84 to 87 cm | 58 |
| 6’1″ to 6’3″ 185 to 190 cm | 34″ to 35″ 86 to 90 cm | 60 |
| 6’3″ to 6’5″ 190 to 195 cm | 35″ to 36″ 89 to 92 cm | 62 |
Mountain bike sizing based on inseam
Compare your inseam measurement against the mountain bike sizes in the table below.
Depending on the mountain bike brand and model, the smallest (XXS) and largest (XXL) might not be available.
| Your height | Your inseam | Mountain bike size |
|---|---|---|
| 4’5″ to 4’9″ 135 to 145 cm | 25″ to 27″ 64 to 68 cm | XXS 13.5″ |
| 4’9″ to 5’1″ 145 to 155 cm | 27″ to 29″ 69 to 73 cm | XS 14.5″ |
| 5’1″ to 5’5″ 155 to 165 cm | 29″ to 31″ 74 to 78 cm | S 15.5″ |
| 5’5″ to 5’9″ 165 to 176 cm | 31″ to 33″ 79 to 83 cm | M 16.5″ |
| 5’8″ to 5’11″ 173 to 180 cm | 32″ to 34″ 81 to 86 cm | M/L 17.5″ |
| 5’10″ to 6’2″ 177 to 188 cm | 33″ to 35″ 84 to 89 cm | L 18.5″ |
| 6’2″ to 6’5″ 188 to 195 cm | 35″ to 36″ 89 to 91 cm | XL 21.5″ |
| 6’5″ to 6’8″ 195 to 203 cm | 36″ to 38″ 91 to 97 cm | XXL 23.0″ |
Hybrid bikes sizing based on inseam
Compare your inseam measurement against the hybrid bike sizes in the table below.
Most bike manufacturers size their hybrid bikes in descriptive ways such as XS, S, M, L, and XL to make it easy for cyclists.
| Your height | Your inseam | Hybrid bike size |
|---|---|---|
| 4’10″ to 5’1″ 147 to 155 cm | 27″ to 29″ 69 to 73 cm | XS |
| 5’1″ to 5’5″ 155 to 165 cm | 28″ to 31″ 72 to 78 cm | S |
| 5’5″ to 5’9″ 165 to 175 cm | 30″ to 33″ 77 to 83 cm | M |
| 5’9″ to 6’1″ 175 to 186 cm | 32″ to 35″ 82 to 88 cm | L |
| 6’1″ to 6’6″ 186 to 197 cm | 34″ to 37″ 87 to 93 cm | XL |
Method 3. Calculating bike size
Calculating the bike size involves a basic understanding of bike frame geometry and your inseam measurements.
The length of the seat tube determines the bike size. The seat tube is the length from the bottom bracket center to the top of the seat tube.
Follow these steps to calculate your bike size.
- Pick the bike type. Each bike type has a specific formula for calculating frame size based on inseam measurement. Here are the most common formulas (source).
- Road bikes. Inseam (cm) x 0.665 = Frame size (cm)
- Mountain bikes. Inseam (cn) x 0.225 = Frame size (inches)
- Hybrid bikes. Inseam (cm) x 0.685 = Frame size (cm)
- Perform the calculation. Apply the appropriate formula and round it up to the nearest whole number.
- Find the size. Match the number to the bike size charts above.
Calculating bike size
Assuming you have a 31″ (79cm) inseam, your road bike size will be 79cm x 0.665 = 52.5cm. Depending on the road bike brand, your size will be either 52cm or 53cm.
Assuming you have a 31″ (79cm) inseam, your mountain bike size will be 79cm x 0.225 = 17.8″. Depending on the mountain bike brand, your size will be between 17″ and 18″.
Method 4. Using the bike manufacturer’s size chart
Bike manufacturers’ size guides offer specific sizing information tailored to each brand and model, ensuring a more accurate and personalized fit than general bike sizing charts or inseam-based calculations.
How to find and use bike manufacturers’ size guides
- Locate the size guide. Visit the bike manufacturer’s website or consult the user manual for the specific model you want. Most manufacturers provide detailed size guides for each of their bike models.
- Identify your measurements. Have accurate measurements of your height and inseam. They are essential for determining the right frame size based on the manufacturer’s recommendations.
- Compare your measurements. Review the size guide and find the frame size corresponding to your height and inseam measurements. Remember that each manufacturer may use different naming conventions for frame sizes (e.g., S, M, L, or 50, 52, 54, etc).
Method 5. Get a professional bike fit
A professional bike fit offers the most accurate, comprehensive, and personalized approach to achieving optimal comfort, efficiency, and performance. The bike fitter can fine-tune every aspect of your riding position, considering your unique body proportions, flexibility, and cycling goals.
The bike fitting process generally includes several stages;
- Pre-fit interview. The bike fitter begins by discussing your riding history, goals, preferences, and any previous injuries or discomfort experienced while cycling. This information helps the fitter understand the rider’s needs and tailor the bike fit accordingly.
- Physical assessment. The fitter physically evaluates your body dimensions, flexibility, and strength. This may include assessing leg length, foot structure, hip flexibility, and spinal curvature, among other factors. The assessment provides crucial data to inform the bike fitting process.
- Initial bike setup. Based on the pre-fit interview and physical assessment, the fitter makes initial adjustments to your bike. This may involve setting the saddle height and fore-aft position, adjusting the handlebar height and reach, and selecting the appropriate stem length. If you don’t have a bike yet, the fitter will use the stationary fitting bike and suggest the ideal bike size for you at the end of the session.
- Cleat positioning and pedal stroke analysis. If you use clipless pedals, the fitter will adjust the cleat position on your cycling shoes to ensure proper foot alignment and efficient pedal stroke. The fitter may use video analysis or motion capture technology to analyze your pedaling technique and make further adjustments as needed.
- On-bike assessment. You ride your bike while the fitter observes your position and pedaling technique. The fitter may make additional adjustments to the bike’s setup, such as fine-tuning the saddle angle or handlebar width, to optimize comfort and efficiency.
- Follow-up and fine-tuning. After the initial bike fit, you may be advised to test ride your bike for a period to evaluate the adjustments made. A follow-up appointment may be scheduled to make any necessary fine-tuning adjustments based on your feedback and comfort.
FAQ
What is the difference between frame size and wheel size?
Frame size refers to the dimensions of a bike’s frame, typically measured in centimeters or inches from the center of the bottom bracket to the top of the seat tube.
On the other hand, wheel size refers to the diameter of the bike’s wheels and is measured in inches.
Can I adjust a bike to fit me better?
Yes, there are several adjustments you can make to improve the fit of a bike, such as adjusting the saddle height, saddle fore-aft position, handlebar height, and stem length.
However, these adjustments have limits, and it’s essential to start with a bike frame that is fundamentally the correct size for your body to ensure the best fit and performance.
Is there a universal bike sizing chart?
While general bike sizing charts can provide a rough estimate of the appropriate frame size based on a rider’s height, it’s essential to remember that bike sizing can vary between different bike brands, models, and types of bikes.
For the most accurate sizing information, consult the bike manufacturer’s size guide or seek the advice of a professional bike fitter.
Should I choose a larger or smaller frame if I am between sizes?
If you find yourself between sizes, choosing a larger or smaller frame depends on your preferences, body proportions, and intended riding style.
- Smaller frame typically offers more maneuverability and a lower standover height, which can be advantageous for technical riding or riders with shorter torso lengths.
- Larger frame generally provides a more stretched-out riding position, which may be more comfortable for riders with longer torsos or those prioritizing stability and comfort over agility.
Test riding both sizes and consulting with a professional bike fitter can help you make the best decision for your needs.
Do men’s and women’s bikes have different sizing?
Some bike manufacturers, such as Liv offer women-specific bike models with geometry and components tailored to better suit the average female body proportions, such as a shorter top tube and narrower handlebars.
What role does standover height play in bike sizing?
Standover height is the distance from the ground to the top of the bike’s top tube. Adequate standover height ensures that you can safely dismount the bike and reduces the risk of injury in case of an unexpected stop.
When standing over the bike with both feet flat on the ground, there should be a clearance of at least 1 to 2” (2.5 to 5 cm) between the top tube and your crotch for road bikes and 2 to 4” (5 to 10 cm) for mountain bikes.