Orbea, the Basque brand, publishes a size guide by height and full geometry on each bike’s page. These are the ones for its best-selling models (Orbea size guide checked in October 2026), cross-checked against the charts of two retailers that sell the brand, Bike Room and My Velo, and the Bike Insights database. Orbea only gives height, not inseam, and notes that its ranges are a guide. It lists them in centimeters; we converted them to feet and inches, rounded to the nearest inch.
Orbea road bike sizes: Orca, Orca Aero and Avant
All three share height ranges. The Orca is the climbing bike, the Orca Aero the aero bike and the Avant the endurance bike: with the same reach, it has a head tube 2 to 3.5 cm taller depending on size.
| Size | Rider height | Orca stack / reach | Avant stack / reach |
|---|---|---|---|
| 47 | 5 ft 1 in–5 ft 3 in (155-160 cm) | 506 / 370 mm | 525 / 370 mm |
| 49 | 5 ft 3 in–5 ft 5 in (160-166 cm) | 515 / 375 mm | 545 / 375 mm |
| 51 | 5 ft 6 in–5 ft 8 in (167-172 cm) | 533 / 380 mm | 565 / 380 mm |
| 53 | 5 ft 8 in–5 ft 10 in (173-179 cm) | 552 / 385 mm | 585 / 385 mm |
| 55 | 5 ft 11 in–6 ft 1 in (180-185 cm) | 572 / 391 mm | 605 / 391 mm |
| 57 | 6 ft 1 in–6 ft 3 in (186-191 cm) | 590 / 398 mm | 625 / 398 mm |
| 60 | 6 ft 4 in–6 ft 9 in (192-207 cm) | 616 / 404 mm | 645 / 404 mm |
Stack is the height of the head tube above the bottom bracket and reach the horizontal distance from the bottom bracket to the head tube: more stack puts you more upright; more reach, more stretched out.
Orbea gravel bike sizes: Terra
| Size | Rider height | Terra stack / reach |
|---|---|---|
| XS | 5 ft 1 in–5 ft 5 in (155-166 cm) | 535 / 386 mm |
| S | 5 ft 6 in–5 ft 8 in (167-172 cm) | 558 / 392 mm |
| M | 5 ft 8 in–5 ft 10 in (173-179 cm) | 580 / 400 mm |
| L | 5 ft 11 in–6 ft 1 in (180-185 cm) | 602 / 406 mm |
| XL | 6 ft 1 in–6 ft 3 in (186-191 cm) | 625 / 412 mm |
| XXL | 6 ft 4 in–6 ft 9 in (192-207 cm) | 645 / 417 mm |
From S to XXL, the ranges are the same as the 51 to the 60 on the road bikes; the XS covers what the 47 and 49 cover there. The Terra Race, the race version, shows the same heights on Orbea’s site, but we haven’t found a second source to confirm it.
Orbea mountain bike sizes: Alma, Oiz and Laufey
The Alma (race hardtail) and the Oiz (XC and marathon full suspension) share a chart. The Laufey, a trail hardtail, has lower ranges: at the same height you may be one size up.
| Size | Alma and Oiz | Laufey |
|---|---|---|
| S | 5 ft 1 in–5 ft 7 in (155-170 cm) | 4 ft 11 in–5 ft 5 in (150-165 cm) |
| M | 5 ft 5 in–5 ft 11 in (165-180 cm) | 5 ft 3 in–5 ft 9 in (160-175 cm) |
| L | 5 ft 10 in–6 ft 3 in (178-190 cm) | 5 ft 7 in–6 ft 1 in (170-185 cm) |
| XL | 6 ft 1 in–6 ft 6 in (185-198 cm) | 5 ft 11 in–6 ft 6 in (180-198 cm) |
We’ve left out the Occam (trail) and the Rallon (enduro): Orbea’s current guide and the retailers’ charts don’t agree on their large and XL sizes, and we’d rather not publish doubtful numbers. If you’re interested in them, check the size guide on their pages at orbea.com.
If you’re between two sizes
Orbea’s ranges touch (160 cm, about 5 ft 3 in, appears in both the 47 and the 49) and on mountain bikes they overlap by several centimeters. To decide:
- On road bikes, going up a size barely adds length: reach grows 5-7 mm, but stack rises about 20 mm (9 to 26 depending on size). If what you want is a more upright position, the Avant in your size gives you a taller front end (585 mm in the 53) than an Orca one size larger (572 mm in the 55).
- On mountain bikes, the smaller size is more agile on twisty trails; the larger one, more stable on fast descents and long rides.
- Inseam: Orbea doesn’t list it. If your legs are long for your height (short torso), lean toward the smaller size, which has less reach, and run more seatpost; if they’re short (long torso), toward the larger one.
Measure your inseam as described in how to find your bike size, get a starting size from the bike size calculator, and put the two candidate sizes, or your current bike, into the bike geometry comparison. To see what size you’d ride in other brands, check the size chart by brand.
Frequently asked questions
What size Orbea Orca do I need if I'm 5'9"?
A 53, which Orbea recommends for 5 ft 8 in to 5 ft 10 in (173-179 cm). It's the same size on the Orca Aero and the Avant; on the Terra gravel bike, a medium, with the same range.
Are an Orca and an Avant in the same size the same fit?
They have the same height ranges and the same reach, but the Avant has a taller head tube: in a 53, 585 mm of stack versus 552 mm on the Orca. You sit more upright without changing size.
What size Orbea mountain bike do I need if I'm 5'11"?
On the Alma and Oiz you're in the overlap between the medium (5 ft 5 in to 5 ft 11 in, 165-180 cm) and the large (5 ft 10 in to 6 ft 3 in, 178-190 cm); on the Laufey, between the large (5 ft 7 in to 6 ft 1 in) and the XL (5 ft 11 in to 6 ft 6 in). Go smaller for agility and larger for long rides or fast descents.
Does Orbea take inseam into account?
Not in its size guide: it only lists height. If your legs are long or short for your height, measure your inseam and compare the geometry of the two candidate sizes.
Sources
- Orbea: Orca M30, size guide and geometry
- Orbea: Orca Aero M30i LTD, size guide
- Orbea: Avant H30, size guide and geometry
- Orbea: Terra M30 Team 1X, size guide and geometry
- Orbea: Alma M20, size guide
- Orbea: Oiz M20, size guide
- Orbea: Laufey H10, size guide
- Bike Room (retailer): Orbea road bike size guide, with stack and reach (July 2026)
- My Velo (retailer): Orbea size guide by model
- Bike Insights: 2026 Orbea Terra geometry (from orbea.com)