Flying around Latin America, the first question is not the size of your bag but whether your fare includes one. Six of the eight airlines in this guide include a cabin bag on the fare shown below: LATAM, Copa, Azul, GOL, Volaris and Viva Aerobus. On Avianca's Basic fare and Wingo's GO BASIC fare, only the small personal item is free and the overhead-bin bag is sold as an extra.
Basic fares sell the bag separately
Avianca sells a 10 kg cabin bag of up to 55 × 35 × 25 cm on its Basic fare. Wingo's paid bag is larger, 55 × 45 × 25 cm and 12 kg, and the same bag is included in its Go Standard, Go Plus and Go Extra fares. LATAM works the same way: Economy Light, Standard and Full include a 12 kg bag, while Economy Basic does not, and the bag can be added through My trips up to 6 hours before the flight.
The 35 cm width
LATAM, Avianca, Azul and GOL all write their cabin bag as 55 × 35 × 25 cm, wheels and handles included on LATAM, Avianca and Azul. A case 40 cm wide is 5 cm too wide for all four. Copa allows 22 × 14 × 10 in (56 × 36 × 26 cm), Viva Aerobus 22 × 16 × 10 in, and Wingo 55 × 45 × 25 cm, the widest of the eight. Azul adds a 115 cm total for the three sides.
Weight limits are not the same
Avianca, Azul and Copa allow 10 kg. LATAM, GOL and Wingo allow 12 kg, and LATAM raises it to 16 kg in Premium Economy and Premium Business. Viva Aerobus allows 33 lb (about 15 kg) on its Smart fare and 22 lb on Switch when you choose a carry-on. Volaris counts differently: two cabin bags of up to 22.4 × 15.7 × 12.9 in each, but 22 lb in total, including your handbag, backpack and electronics.
The personal item
LATAM, Avianca and Azul share the same personal item, 45 × 35 × 20 cm; Azul also caps it at 100 cm in total with no weight limit. GOL allows 32 × 22 × 43 cm and up to 10 kg. Copa allows 17 × 10 × 9 in, Viva Aerobus 18 × 14 × 8 in and Wingo 40 × 35 × 25 cm.
Flying from the United States
On Volaris, flights from the United States follow a TSA rule that allows only two small cabin bags per passenger. A US carry-on of 22 × 14 × 9 in measures 55.9 × 35.6 × 22.9 cm: it fits Copa, Viva Aerobus and Volaris, but it is 0.9 cm too long for the 55 cm limit of LATAM, Avianca, Azul, GOL and Wingo, and 0.6 cm too wide for the 35 cm of the first four.
One bag for the whole region
The figures below give the largest bag that all eight airlines accept. If you change airlines during the trip, pack to that box and to the lowest weight shown, and remember that two of the eight sell the cabin bag only as an extra on their basic fares.