Start with your height, then check the model's own chart. Here is the general guide, what to do when you fall between sizes, and the two numbers that really decide fit.
Pick a bike type and enter a height.
These are typical ranges across the industry. Brands vary by a size either way, which is why every bike page on BikeFinder uses that model's own chart where we have one.
| Size | Height | Feet |
|---|---|---|
| XS48 to 50 cm frame | 152 to 160 cm | 5 ft 0 in to 5 ft 3 in |
| S51 to 52 cm frame | 160 to 167 cm | 5 ft 3 in to 5 ft 6 in |
| M53 to 54 cm frame | 167 to 174 cm | 5 ft 6 in to 5 ft 9 in |
| ML55 to 56 cm frame | 174 to 181 cm | 5 ft 9 in to 5 ft 11 in |
| L57 to 58 cm frame | 181 to 188 cm | 5 ft 11 in to 6 ft 2 in |
| XL59 to 61 cm frame | 188 to 196 cm | 6 ft 2 in to 6 ft 5 in |
| Size | Height | Feet |
|---|---|---|
| XS | 142 to 155 cm | 4 ft 8 in to 5 ft 1 in |
| S | 152 to 165 cm | 5 ft 0 in to 5 ft 5 in |
| M | 165 to 177 cm | 5 ft 5 in to 5 ft 10 in |
| L | 177 to 188 cm | 5 ft 10 in to 6 ft 2 in |
| XL | 188 to 198 cm | 6 ft 2 in to 6 ft 6 in |
| Size | Height | Feet |
|---|---|---|
| XS | 145 to 157 cm | 4 ft 9 in to 5 ft 2 in |
| S | 155 to 167 cm | 5 ft 1 in to 5 ft 6 in |
| M | 165 to 177 cm | 5 ft 5 in to 5 ft 10 in |
| L | 177 to 188 cm | 5 ft 10 in to 6 ft 2 in |
| XL | 188 to 198 cm | 6 ft 2 in to 6 ft 6 in |
| Wheel | Height | Feet |
|---|---|---|
| 12 inch | 85 to 105 cm | 2 ft 9 in to 3 ft 5 in |
| 14 inch | 95 to 115 cm | 3 ft 1 in to 3 ft 9 in |
| 16 inch | 105 to 120 cm | 3 ft 5 in to 3 ft 11 in |
| 20 inch | 115 to 135 cm | 3 ft 9 in to 4 ft 5 in |
| 24 inch | 130 to 150 cm | 4 ft 3 in to 4 ft 11 in |
| 26 inch | 145 to 160 cm | 4 ft 9 in to 5 ft 3 in |
Frame size labels are not standard, so a medium from one brand can ride like a large from another. Stack (height of the front of the frame) and reach (its length) are measured the same way by everyone. If a bike you like fits you well, look for another with a similar stack and reach in the Geometry Lab, or put them side by side in the comparison engine and see the frames drawn on top of each other.
As a starting point, riders around 167 to 174 cm usually fit a medium road bike (53 to 54 cm) and a medium mountain bike. Every brand sizes differently, so check the chart for the exact model; BikeFinder shows it on each bike page where we have it.
Choose the smaller size for a shorter reach, a more upright position and quicker handling, or the larger size for more stretch and stability at speed. Riders with long arms and legs for their height often suit the larger size.
Many road and gravel brands use centimetres (for example 54 or 56), which roughly reflects the seat tube length. Others use S, M, L. Compare the brand's rider height chart rather than the number alone.
Kids bikes are sized by wheel diameter. As a rough guide, 16 inch wheels suit children about 105 to 120 cm tall and 20 inch wheels about 115 to 135 cm. Your child should be able to put both feet down comfortably.
Stack is how high the handlebar end of the frame sits above the pedals, and reach is how far forward it is. More stack is more upright; more reach is more stretched out. They are the best way to compare fit between brands.