Airfare Brain

Airfare Brain gives the true cost of a flight once the extras are added: bags, seats, priority boarding, airport check-in, changes and payment fees, on 29 airlines in Europe and North America, including Ryanair, easyJet, Wizz Air, Jet2, British Airways, Lufthansa, KLM, Air France, Iberia, Turkish Airlines, Delta and United.

Every price is taken from the airline's own fee pages and returned with its source link and the date it was checked. Where an airline publishes no price, the answer says so (or gives a figure labelled with the third party that reported it); an unknown fee is never counted as free.

Ask it to:

• add the bags and seats you want to a fare you found, for the whole party and both flights;
• compare airlines once bags are included (the cheapest fare is often not the cheapest trip);
• show what an extra costs online versus at the airport;
• price a whole trip into one airport, including what car hire there really costs (from its sister site, Car Rental Brain).

Read-only, no account, nothing personal requested. It has no live fares and never books: give it the fare from any flight search. The airfarebrain.com website's flight search links to Kiwi.com through an affiliate programme; the tools themselves return fee data only.

Limitations: published ranges, not quotes for a specific flight; airlines change fees, so each answer carries the date it was checked.