STM Prime vs. Patagonia Atom Tote Pack 20L
Two carry-on travel backpacks, compared spec for spec.
STM Prime
| Capacity | 15 L |
| Weight | 0.7 kg |
| Dimensions | 42×26×13 cm |
| Airline fit | 96% |
| Price | $80 |
Feature by feature
| STM Prime | Feature | Patagonia Atom Tote Pack 20L |
|---|---|---|
| Storage | ||
| N | Compression | N |
| None | Expanded Capacity | None |
| 0 | Opening | 0 |
| top | Passport | front |
| N | Passthrough | N |
| Carry | ||
| Y | Backpack | Y |
| N | Hip Belt | N |
| Y | Sternum Strap | removable |
| Inside | ||
| 13in | Laptop | 13in |
| 2 | Main Compartments | 2 |
| N | Organizer | Y |
| Outside | ||
| × | Hard Shell | × |
| N | Rain-fly | N |
| 2, side | Water Bottle Holder | 2, side |
| Y | Water Resistant | Y |
| Material | |
| Polyester | 7.3-oz 400-denier recycled Polyester with DWR Finish |
Patagonia Atom Tote Pack 20L
| Capacity | 20 L |
| Weight | 0.6 kg |
| Dimensions | 41×30×13 cm |
| Airline fit | 95% |
| Price | $90 |
Key differences between the STM Prime and Patagonia Atom Tote Pack 20L
- Passport pocket: Top on the STM Prime; Front on the Patagonia Atom Tote Pack 20L.
- Sternum strap: Yes on the STM Prime; Removable on the Patagonia Atom Tote Pack 20L.
- Built-in organizer: No on the STM Prime; Yes on the Patagonia Atom Tote Pack 20L.
Both have: backpack straps, laptop sleeve, water bottle pockets, water resistant.
Which airlines take each bag as a carry-on
We checked both bags against the carry-on size limits of 189 airlines. 180 accept both. 1 accept only the STM Prime, and 0 accept only the Patagonia Atom Tote Pack 20L.
Only the STM Prime fits
Great Lakes Airlines.
STM Prime vs. Patagonia Atom Tote Pack 20L: which should you pack?
The Patagonia Atom Tote Pack 20L carries 5L more than the STM Prime (15L vs. 20L), while the Patagonia Atom Tote Pack 20L is the lighter pack at 0.6kg (vs. 0.7kg). For carry-on flexibility, the STM Prime fits 96% of the airlines we track — the higher of the two. If you prioritise packing volume, choose the Patagonia Atom Tote Pack 20L; if you want to travel lighter, the Patagonia Atom Tote Pack 20L is the better call.