What each card does
A flat-rate card pays the same rate on every purchase, often 1.5% or 2%.
A category card pays a higher rate, often 3% to 6%, in a few categories, and a base rate of about 1% elsewhere.
The category card loses money compared with the flat-rate card on every purchase outside its categories.
Do the arithmetic
Add up your spend in each bonus category. Multiply by the extra rate the category card pays over the flat-rate card.
Check the caps. Spend past a cap earns the base rate, often less than the flat rate.
Subtract any annual fee. The result is what the category card adds.
Why both is usually best
Use the category card inside its category and the flat-rate card everywhere else.
The difficulty is remembering which is which at the register.
CardSwipe answers that at the moment you pay.
