How CardMatchly works out which card earns the most
CardMatchly tells you which card in your wallet earns the most miles for a purchase, before you pay. Here is where the numbers come from, how they are calculated, and what CardMatchly does not do.
Where the card data comes from
Card data comes from official bank sources.
How miles per dollar (mpd) is calculated
Miles per dollar is the number of air miles a card earns for each dollar you spend. A card that earns 4 mpd turns a $100 purchase into 400 miles.
- Best rate. The “up to” rate on each card page is the highest rate the card earns on any kind of spending. Most spending earns less, so it is a ceiling, not an average.
- Spending blocks. Some cards award bonus miles per block of spend, for example per $5. A $14 purchase on a $5-block card earns bonus miles on $10, not $14.
- Bonus caps. Bonus rates usually stop after a set amount of spending per month or statement cycle. Past the cap, the card drops to its base rate until the cap resets.
- Overseas spending. A foreign currency fee is a cost on every overseas purchase, so CardMatchly weighs it against the miles earned instead of looking at the earn rate alone.
How a recommendation is made
You tell CardMatchly which cards you hold. You never connect a bank account or enter a card number. When you ask about a purchase, CardMatchly matches the merchant to a spending category, applies each of your cards' rules for that category and payment method, takes account of caps you have already used if you log your spending, and ranks the top 3 cards in your wallet.
An AI model reads your question and applies the card rules from the database. It can make mistakes, so for large purchases, check the bank's own terms before you pay.
Independence
CardMatchly is independent and is not paid by any bank to list, rank or recommend cards. A card's position in a recommendation depends only on how many miles it earns for that purchase in your wallet.
Who is behind CardMatchly
CardMatchly was built in 2026 by its founder, Wendy, a miles enthusiast who wanted a way to know which card to use before every purchase without handing over bank logins. Read why she built it.
General information, not financial advice. Banks set their own rates, limits, fees and rules, and change them from time to time, so check with the bank before you apply.