MTB and Gravel Bike Sizing: Size Charts, Wheel Size, Stack and Reach
Updated · Written by Stas Bashylov, Ihor Twin
A size chart is a quick way to narrow down which mountain or gravel frame to look at. The charts below are general estimates based on one retailer’s published size guide, not a universal sizing standard. Brands label and design their frames differently, so always check the specific bike’s geometry — especially stack and reach — before you buy.
Mountain bike size chart by height and inseam
| Size | Rider height | Inseam | Suggested wheel |
|---|---|---|---|
| XS (13.5") | 137–155 cm | 64–73 cm | 26" or 27.5" |
| S (15.5") | 153–166.5 cm | 72–79 cm | 27.5" or 29" |
| M (17.5") | 161–172 cm | 76–81 cm | 27.5" or 29" |
| M/L (18.5") | 165.5–179 cm | 77–84 cm | 29" or 27.5" |
| L (19.5") | 177–188 cm | 83–88 cm | 29" or 27.5" |
| XL (21.5") | 186–196 cm | 87–92 cm | 29" or 27.5" |
| XXL (23.0") | 195–203 cm | 92–95 cm | 29" or 27.5" |
Gravel bike sizes
In the source chart, gravel bikes follow road-bike frame sizing in centimetres:
| Frame size | Rider height | Inseam |
|---|---|---|
| 47 cm | 152–158 cm | 71–75 cm |
| 50 cm | 158–163 cm | 74–77 cm |
| 52 cm | 163–168 cm | 76–79 cm |
| 54 cm | 168–174 cm | 78–82 cm |
| 56 cm | 174–180 cm | 81–85 cm |
| 58 cm | 180–185 cm | 84–87 cm |
| 60 cm | 185–190 cm | 86–90 cm |
| 62 cm | 190–195 cm | 89–92 cm |
How to choose between sizes
- Find the row where both your height and your inseam fit.
- If you are between sizes or the ranges overlap, compare stack (how high the front of the bike is) and reach (how long it is) of the candidate frames. A smaller size usually puts the handlebars lower and closer, a larger one higher and further away.
- On a mountain bike, many riders also look at standover — room to put a foot down and move around the bike on rough ground.
- Stem length, spacers and saddle position can fine-tune the fit only within limits. If you can, test-ride both sizes or ask a bike fitter.
What the bike fit calculator adds
- Gravel: the bike fit calculator suggests a frame size from the gravel chart and estimates a frame reach range. This is the calculator’s own rough estimate (stack ≈ inseam × 0.67, divided by a stack-to-reach ratio of 1.46–1.55), not a manufacturer’s figure. For example, an 85 cm inseam gives about 367–390 mm of reach — compare it with the reach in each model’s geometry chart.
- XC mountain bike: the calculator suggests a size from the MTB chart and a handlebar width of 640–740 mm. It does not estimate frame reach for mountain bikes, because its methodology has no sourced method for it.
- Saddle height for both starts from inseam × 0.883, with −2 mm for gravel and −5 mm for XC — see the saddle height guide.
Measure before you use the chart
Measure your height barefoot and your inseam with the book-against-the-wall method — see how to measure your inseam. The bike size guide shows all charts and highlights the rows matching your measurements. For the fit differences between road and mountain bikes, see road vs. mountain bike fit.
Frequently asked questions
What size mountain bike do I need for my height?
As a general estimate from the chart, 161–172 cm often fits an M, 165.5–179 cm an M/L and 177–188 cm an L. The ranges overlap, so check your inseam and compare stack and reach on the specific bike, because brands size their frames differently.
Is gravel bike sizing the same as road bike sizing?
In the source chart, yes: gravel bikes use the same centimetre sizes as road bikes. Geometry still varies between models, so compare stack and reach rather than relying on the size number.
Which wheel size should I choose for my mountain bike size?
The chart suggests 26" or 27.5" for XS, 27.5" or 29" for S and M, and 29" or 27.5" from M/L up. Check which wheel size the specific model uses in your size.
The chart puts me in two sizes. What now?
Overlapping ranges are normal. Use your inseam as a tiebreaker, then compare stack and reach of both sizes. If you can, test-ride both or ask a bike fitter.
Sources
- The Bike Shoppe, bike size guide (general size ranges used in the tables).