BTS day passes cost 140 baht but you need 8+ rides to break even, and most tourists don't come close to that. Individual rides cost 16-44 baht depending on distance, so unless you're doing some ridiculous temple-hopping marathon, you're wasting money.

I tracked my actual usage last trip: Grand Palace via Saphan Taksin (44 baht), Chatuchak Weekend Market (42 baht), back to Siam (28 baht), then Asok for dinner (22 baht). Total: 136 baht. The day pass would've cost 140 baht plus 20 minutes queuing to buy it, while contactless payment takes literally 2 seconds.

Even worse, the day pass doesn't work on Airport Rail Link or boats, so you'll still need separate tickets for half your journey anyway. The tourist information desks push these passes hard because they get commission - ignore them completely.

Just use contactless payment or buy a Rabbit Card with 100-200 baht credit. You'll spend less, move faster through stations, and won't feel obligated to take unnecessary BTS rides just to "get your money's worth." Bangkok's heat makes that last point particularly stupid.