Methodology
How credit card interest drag is modeled
The model accrues monthly interest, applies a fixed payment, and estimates first-year interest, payoff time, and total interest.
Default APR benchmark
21.50%
Formula
Monthly interest equals remaining balance x APR / 12. SwitchWize applies the modeled monthly payment until the balance reaches zero or the payment fails to cover accruing interest.
Related: Credit Card Interest Drag Index and JSON dataset.
Public source posture
- FDIC National Rates and Rate Caps
- Federal Reserve FRED checkable deposits series BOGZ1FL193020005Q
- TreasuryDirect auction results
- Federal Reserve G.19 consumer credit
- Investment Company Institute money market fund statistics
Refresh current-rate claims from primary sources before publishing a new monthly snapshot or changing headline numbers.