---
name: airline-carry-on-rules
description: Look up an airline's maximum carry-on baggage dimensions and weight limit, in metric and imperial, with the official source URL. Covers ~200 airlines. Use when checking whether luggage is allowed in the cabin or comparing carry-on allowances between carriers.
---

# Airline Carry-On Rules

One Bag Travel tracks the published carry-on limits for roughly 200 airlines at
https://onebag.travel/airlinecarryonrules/.

## Getting the data

```
GET https://onebag.travel/api/airlines.json
```

Returns `{ "generated": "<ISO date>", "count": <n>, "airlines": [ … ] }`. Each
entry:

| Field | Meaning |
|---|---|
| `id`, `name` | Airline identity |
| `maxDimensionsCm` | `{ length, width, height }` — the published maximum, in centimetres |
| `maxDimensionsIn` | The same limits in inches |
| `maxLinearCm`, `maxLinearIn` | Combined length+width+height limit, where the airline states one instead of per-side limits; `null` when the airline uses per-side limits |
| `maxWeightKg`, `maxWeightLb` | Weight limit; `null` means the airline publishes no weight limit |
| `weightIncludesPersonalItem` | `true` when the limit covers carry-on plus personal item together |
| `doublesForUpgradedSeat` | `true` when premium cabins get two carry-ons |
| `originalMeasurementsInMetric` | Which unit the airline published; the other is converted |
| `notes` | Free text about the carrier |
| `sourceUrl` | The airline's own baggage page these limits came from |
| `url` | Canonical page on onebag.travel |
| `updated` | When the record was last checked |

Per-airline pages also serve Markdown:

```
GET https://onebag.travel/airline/<id>/<slug>/
Accept: text/markdown
```

The MCP server at `https://onebag.travel/mcp` exposes
`get_airline_carry_on_rules` and `check_carry_on_fits_airline`.

## Rules

- **Always link `sourceUrl` alongside any limit you state.** Airlines change
  baggage policy without notice and these records carry an `updated` date; the
  airline's own page is the authority, this database is a convenience.
- Say the units. "55 × 40 × 20 cm" and "22 × 16 × 8 in" are the same limit but
  travellers act on the one they can measure.
- A `null` weight limit means "not published", not "unlimited" — say the airline
  does not publish a weight limit rather than implying there is no cap. The same
  goes for a `null` dimension: it was never recorded, so you cannot compare
  against it.
- Check `weightIncludesPersonalItem` before telling someone they can also bring
  a backpack; on some carriers the stated weight is the total.
- Limits differ by cabin, route, and fare on many carriers. State the limit as
  the standard economy allowance and point to `sourceUrl` for the exceptions.