How this is calculated
Each card's reward structure — category rates, spending caps, annual fee — is applied to your monthly amounts, annualized:
annual value = Σ ( category spend × category rate, up to the card's cap ) − annual fee
Capped categories matter more than headlines: a "6% on groceries" card capped at $6,000/year earns at most $360 from groceries no matter how much you spend. Rotating 5% cards are credited here at their realistic effective rate on "everything else" style spending rather than a best-case fantasy.
Why the winner changes as you type
Flat 2%-on-everything cards win for spread-out spending; category cards win when one category dominates. The crossover is exactly what this tool finds — try moving your grocery number and watch the ranking reorder.
Data integrity
Reward structures are compiled from issuers' published terms (date shown above) and stored in one open data file anyone can inspect. Some links on our accounts & cards page may be affiliate links — they never affect rates shown here or the ranking, which is pure arithmetic on your numbers.