London and Paris carry-on: museum bag limits
The Louvre says "Any items exceeding 55 x 35 x 20 cm will not be allowed in the museum", and the British Museum says "Wheeled cases are not permitted regardless of their size and weight". Our pick is a small sling inside both limits for check-out day, with the main bag stored; in London the British Museum points to "major rail stations, including Euston, King's Cross and Charing Cross". The trade-off is carrying two bags, and flying home from Paris, liquids over 100 ml aren't allowed in cabin bags.
Check-out day at the Louvre and the British Museum
On the day you leave, the hotel room is gone and the bag comes with you. Both museums set a limit on what you carry in, and the two limits aren't the same. We read each museum's own page on 19 Oct 2026.
Louvre
The Louvre's museum-rules page says: "Suitcases and large bags are not allowed in the museum." It then gives a size: "Please note: Any items exceeding 55 x 35 x 20 cm will not be allowed in the museum (welcome area and exhibition rooms)." For smaller things, the same page says "lockers are available free of charge for smaller items", and "All items left in the lockers must be collected the same day."
The page doesn't say whether wheels or straps count toward 55 x 35 x 20 cm, so we'd measure the whole bag. It also shows a "Vigipirate en posture Vigilance renforcée" notice, and rules can change with the security level, so check the museum-rules page before you go.
British Museum
The British Museum's visit page bars large items of luggage from the Museum and its premises "For security reasons", and gives the limit in brackets: "bigger than 40cm x 40cm x 50cm and heavier than 8kg". Wheels are a separate line: "Wheeled cases are not permitted regardless of their size and weight." For the bag you can't bring in, it says "Storage for luggage is available at major rail stations, including Euston, King's Cross and Charing Cross."
The Visitor and Member cloakroom lists "Opening hours: 10.00–17.00 (20.30 on Fridays)." It adds: "Last deposits are one hour before closing time." and "Please collect items 30 minutes before closing time."
Side by side, by our reading, the Louvre sets a size, and the British Museum sets a size, a weight and a ban on wheeled cases. Take the Osprey Farpoint 40, the backpack on our other pages, as an example: Osprey lists it at 55 × 35 × 23 cm and 1.48 kg. That's 3 cm deeper than the Louvre's 20 cm, and its 55 cm side is longer than any of the British Museum's three figures. The British Museum joins its size and weight with "and", so by our reading the page leaves open whether a bag over the size but under 8 kg gets in, and we'd plan as if it doesn't. Packed depth varies, and neither page says how its staff check a bag, so we can't promise a result either way. Whether to bring a day bag at all is its own question, covered in our daypack guide.
One r/HerOneBag poster spent a weekend in Paris in early October, travelling by train with a 7 L sling and a small tote for food, water and her jacket (posted 17 Oct 2026). Her reason for the small bag: "My main reason for this set up was that I considered going to some museums before my Sunday train, and I didn't want to have to store my luggage or pay for a locker." On clothes, she wrote: "The amount of clothes was perfect."
Crossing on Eurostar
Eurostar's luggage page is relaxed about liquids: "Forget the tiny bottles and see-through bags – there are no strict liquid limits when you travel with Eurostar." Its comparison table puts it as "No restrictions on liquids (some on alcohol limits)." So the toiletry bag can stay packed on the train. On bag numbers, a Standard ticket covers two pieces plus one piece of hand luggage, and Eurostar says: "On routes to and from London, you can bring a bag up to a maximum length of 85cm, and on all other routes, 75cm." For the rest of a longer rail trip, see the Europe 14-day list.
The flight home: 100 ml from Paris
Paris Aéroport's luggage page says that "when departing from Paris airports, liquids over 100mL are not allowed in cabin baggage (unless purchased after security checks)." On how to pack them: "You can carry them as long as they are less than 100 ml. Keep them in a transparent bag, such as a 1-litre freezer bag. Only 1 bag per person." Airports differ, and Heathrow's own page puts it this way: "Many airports outside Heathrow still have a 100ml liquids limit. Check the rules before your return journey." Check the airport you fly home from; our liquids guide covers the rest.
October and November: what goes in the bag
Long-term averages for 1991 to 2020, one row per station, with station names as each weather service prints them. The figures are normals, which describe past decades and can't forecast your week.
| Station (service, 1991 to 2020) | October: high / low °C | October: rain mm, days ≥ 1 mm | November: high / low °C | November: rain mm, days ≥ 1 mm | What it changes in the bag (by our reading) |
|---|---|---|---|---|---|
| Heathrow (Met Office) | 15.81 / 8.78 | 65.07, 10.80 | 11.47 / 5.26 | 66.63, 11.23 | November's 5.26 °C low: a warm layer for the evenings, worn on travel days |
| PARIS-MONTSOURIS 75114001 (Météo-France) | 16.5 / 9.9 | 55.2, 9.5 | 11.1 / 6.2 | 54.3, 10.4 | Highs and lows close to Heathrow's in both months, so one list covers both cities; 10.4 rain days in November keep the rain layer in |
| Edinburgh, Royal Botanic Garden No 2 (Met Office) | 13.37 / 6.72 | 75.71, 11.73 | 9.86 / 3.77 | 65.25, 11.70 | November's 9.86 °C high: hat and gloves if Edinburgh is on the route |
If Edinburgh is on the route, the Royal Botanic Garden No 2 row is the one that changes the bag. Its November high is 9.86 °C against Heathrow's 11.47, and its October high is 13.37 °C against 15.81. By our reading, that means a warmer layer, plus a hat and gloves for November. For wet-weather gear in Scotland, our rain jacket or umbrella guide works through a Glasgow example.
The list below is our suggestion for about a week of clothes, washed once a week (the laundry guide covers how), with the walking shoes worn and one other pair packed.
Two bags
City clothes
Rain and evening layers
Shoes
For the trip home
Example: Heathrow in, Eurostar across, home from Paris
An example route, to show which rule applies on each day.
- Fly into Heathrow with the Farpoint 40, listed at 55 × 35 × 23 cm and 1.48 kg, checked against your airline's limit in the airline cabin-bag table.
- British Museum day, after check-out. We'd leave the Farpoint at luggage storage in one of the rail stations the museum names. Its 55 cm side is longer than any of the 40cm x 40cm x 50cm figures, and we wouldn't count on staying under 8 kg to get it in. Take the sling in.
- Eurostar to Paris. You can leave the toiletry bag packed, since the train has "no strict liquid limits".
- Louvre day, after check-out. By our reading the Farpoint is 3 cm deeper than the 20 cm in 55 x 35 x 20 cm. We suggest planning the Louvre for a day when you aren't carrying the main bag, and taking the sling in. The Louvre's free lockers are "for smaller items".
- Fly home from Charles de Gaulle or Orly. If every liquid is already 100 ml or less and in a "1-litre freezer bag", as Paris Aéroport puts it, there's nothing to repack, by our reading.
More OneBag Kit guides for this trip
- Layers for a colder trip: cold-weather carry-on.
- If the trip goes on south: the Italy carry-on list.
- What else fits in the main bag: is a 40L backpack big enough.
- The sling under the plane seat: personal-item sizes by airline.
Sources, each read on 19 Oct 2026: Louvre museum rules · British Museum, visit · Eurostar luggage · Paris Aéroport luggage · Heathrow hand baggage and liquids · Met Office location-specific long-term averages, 1991-2020: Heathrow, Edinburgh, Royal Botanic Garden No 2 · Météo-France, Fiche climatologique 1991-2020, PARIS-MONTSOURIS 75114001 (sheet edited 15 Oct 2026), from the data.gouv.fr Fiches climatologiques dataset, Licence Ouverte 2.0 · Osprey Farpoint 40 (checked 8 Oct 2026).