Find the right frame size without seeing the bike
General size charts for road, mountain and hybrid bikes, built from manufacturers’ own guides. Every listing also shows the recommended rider height for that model, and that’s the one to trust.
Check your size
-
Manufacturer sizing first
We bring together size guides from manufacturers’ websites, so you see each brand’s own advice.
-
Rider height on every listing
Each listing shows the recommended rider height for that model, wherever we have it.
-
Sellers add their measurements
We ask sellers for frame measurements and their own height, so you have something to compare against.
Road bikes
Road frames are sized by the length of the seat tube: the tube that runs from the bottom bracket, where the cranks attach, up to the seat post. The figure is in centimetres.
Some brands use XS to XXL instead. It’s less common on road bikes, so the chart gives both.
| Size | Frame | Rider height | Rider height (cm) |
|---|---|---|---|
| XXS (your size) | 47–48 cm | Under 5′0″ | Under 152 cm |
| XS (your size) | 49–50 cm | 5′0″–5′3″ | 152–160 cm |
| S (your size) | 51–53 cm | 5′3″–5′6″ | 160–168 cm |
| M (your size) | 54–55 cm | 5′6″–5′9″ | 168–175 cm |
| L (your size) | 56–58 cm | 5′9″–6′0″ | 175–183 cm |
| XL (your size) | 59–62 cm | 6′0″–6′3″ | 183–191 cm |
| XXL (your size) | Over 62 cm | 6′3″–6′6″ | 191–198 cm |
Mountain bikes
Mountain bikes are measured the same way as road bikes, but most modern frames have a steeply sloping top tube. That makes seat tube length vary a lot between brands, so it tells you less.
That’s why mountain bikes are usually sold as Small, Medium, Large and so on. Go by the letter, and use the centimetres as a cross-check.
| Size | Frame | Rider height | Rider height (cm) |
|---|---|---|---|
| XS (your size) | 33–37 cm | 4′10″–5′2″ | 148–158 cm |
| S (your size) | 38–42 cm | 5′2″–5′6″ | 158–168 cm |
| M (your size) | 43–47 cm | 5′6″–5′10″ | 168–178 cm |
| L (your size) | 48–52 cm | 5′10″–6′1″ | 178–185 cm |
| XL (your size) | 53–57 cm | 6′1″–6′4″ | 185–193 cm |
| XXL (your size) | 58–61 cm | 6′4″–6′6″ | 193–198 cm |
Hybrid bikes
Hybrids sit between road and mountain bikes in their geometry. Brands size them in centimetres, inches or Small, Medium, Large, sometimes all three.
This chart gives every format, so you can match whatever the listing uses.
| Size | Frame (cm) | Frame (in) | Rider height | Rider height (cm) |
|---|---|---|---|---|
| XS (your size) | 33–37 cm | 13–14″ | 4′10″–5′2″ | 148–158 cm |
| S (your size) | 38–42 cm | 15–16″ | 5′2″–5′6″ | 158–168 cm |
| M (your size) | 43–47 cm | 17–18″ | 5′6″–5′10″ | 168–178 cm |
| L (your size) | 48–52 cm | 19–20″ | 5′10″–6′1″ | 178–185 cm |
| XL (your size) | 53–57 cm | 21–22″ | 6′1″–6′4″ | 185–193 cm |
| XXL (your size) | 58–61 cm | 23–24″ | 6′4″–6′6″ | 193–198 cm |
Between two sizes?
Height gets you close. The listing, the seller and a few measurements decide the rest.
- Check the listing firstThe manufacturer’s recommended rider height for that exact model beats any general chart, including these.
- Compare with the sellerMany sellers give their own height. If they’re close to yours and the bike fitted them, that’s a good sign.
- Ask for the measurementsMessage the seller from the listing for the seat tube and top tube lengths, and the model year so you can look up the brand’s geometry.
- Fine-tune once it arrivesSaddle height, saddle position and stem length adjust the fit. The frame size can’t change, so get that right first.
Questions people ask about sizing
Can’t see yours? Our Ride Guides can help you find the right size.
Is a medium the same size across brands?
No. Each brand designs its own geometry, so a medium from one can fit like a large from another. That’s why the manufacturer’s recommended sizing on each listing is the one to trust, and these charts are a general guide.
How do I measure a frame myself?
Measure along the seat tube, from the centre of the bottom bracket (where the cranks attach) to the top of the tube, in centimetres. On mountain bikes with a sloping top tube this number tells you less, so go by the brand’s Small, Medium, Large sizing.
What if a listing doesn’t show a rider height?
Ask the seller for the frame size, the model year and their own height. With the brand, model and year you can check the manufacturer’s size guide for that exact bike.
I’m right on the line between two sizes. Which do I pick?
Start with the rider height on the listing, since it’s specific to that model. If it’s still close, compare against the seller’s height and ask for the frame measurements, or talk to one of our Ride Guides before you buy.
Do the charts cover electric and gravel bikes?
Electric bikes follow the chart for their style: an electric road bike sizes like a road bike, an electric mountain bike like a mountain bike. Gravel bikes are sized like road bikes, in centimetres, though some brands use Small, Medium, Large.