📏 Bike Frame Size Calculator
Enter your height (and inseam for a sharper result) and pick a bike type to get a recommended frame size, a size range, and the full height-to-size chart.
A starting point — geometry varies by brand, so always test-ride before buying.
🧮 Find Your Frame Size
📏 Recommended frame size
| Rider height | Frame size | Label |
|---|---|---|
| 0–160 cm | 48–50 cm | XS |
| 160–170 cm | 50–53 cm | S |
| 170–178 cm | 53–56 cm | M |
| 178–185 cm | 56–58 cm | L |
| 185–193 cm | 58–61 cm | XL |
| 193 cm and up | 61–63 cm | XXL |
Get the size right before you buy
A frame that's too big or too small is uncomfortable, slower, and hard to fix with parts. Getting the size close from the start — using your height and, ideally, your inseam — saves you money and makes every ride more comfortable, whether you're buying road, mountain or hybrid.
This calculator combines a height-to-size chart with the inseam formula fitters use, and shows the right unit for each bike type. Read exactly how the sizing works in the FAQ below.
❓ Frequently Asked Questions
How is bike frame size calculated?
This tool uses two methods. The primary one is a height-to-size chart tailored to each bike type. It also offers an inseam formula, which many fitters prefer because leg length drives standover more than total height: for a road bike, frame size in centimetres ≈ inseam (cm) × 0.665; for a hybrid, ≈ inseam × 0.685; for a mountain bike, frame size in inches ≈ inseam (cm) × 0.226. Enter both height and inseam for the best result.
Why are road bikes measured in cm and mountain bikes in inches?
It's convention. Road frames are traditionally sized by the seat-tube length in centimetres (48, 52, 56 cm, and so on), while mountain bikes are usually sized in inches (15, 17, 19 in) or as S/M/L. Hybrids and city bikes follow the road convention in centimetres or use S/M/L. The calculator shows the right unit for the bike type you pick, alongside a letter size.
Should I size up or size down between two frames?
If you fall between sizes, your riding style decides. Choose the smaller frame for a more agile, aggressive fit and easier standover — common for spirited road and technical mountain-bike riding. Choose the larger frame for a more relaxed, stretched-out position and stability on long rides. Reach and stack matter as much as the headline size, and a stem or seatpost swap can fine-tune either choice.
How accurate is this frame size recommendation?
It's a solid starting point, not a substitute for a proper bike fit. Frame geometry varies between brands and even between models from the same brand, so a '54' from one maker won't fit exactly like a '54' from another. Body proportions — long legs versus a long torso — also shift the ideal size. Always test-ride before buying, and consider a professional fit for an expensive bike.