APR vs. Interest Rate: Which Cost Belongs in Your Comparison?
Interest rate prices the use of principal. APR tries to express interest plus certain finance charges as an annual rate. Neither replaces the cash-flow schedule.
True APR Calculator
Turn the money you actually receive and repay into one comparable annual rate.
Scope: This is an effective cash-flow rate estimate, not a lender’s statutory APR disclosure. Legal APR rules determine which charges a disclosed APR must include.
Calculations stay in this browser. No entries are saved.
Follow the money that actually changes hands
The quoted rate sits on the contract. The effective cash-flow rate comes from the smaller amount received and every required payment that follows.
- Cash received after deductions
- Payments plus recurring charges
- One comparable annualized rate
Effective rate and total finance cost
Calculated resultNot available
Check whether each charge is mandatory, when it is paid and whether it reduces proceeds or changes a later payment.
Follow principal and interest through the term
This annual summary groups the scheduled monthly payments. Upfront and recurring fees affect total borrowing cost but do not reduce principal in this balance schedule.
| Year | Starting balance | Principal paid | Interest paid | Ending balance |
|---|
Rounded display values can differ slightly from a lender schedule. Verify payment dates, day-count rules and final-payment adjustments in the contract.
How the cash-flow rate is solved
The payment is calculated from the stated rate and principal. Net proceeds equal the loan amount minus upfront fees. We then use bisection to find the monthly rate at which the present value of payments plus recurring charges equals those proceeds; the displayed effective annual rate compounds that monthly rate for 12 periods.
Effective annual rate = (1 + monthly cash-flow rate)12 − 1
What this APR estimate cannot decide
The estimate assumes equal end-of-month payments and that all entered fees are mandatory finance costs. It does not predict variable-rate changes, late fees, optional products, taxes or prepayment behavior.
This calculator supports The Real Cost of Borrowing. APR vs. Interest Rate: Which Cost Belongs in Your Comparison? explains which details can change the inputs. The calculation methodology shows how we handle timing, rounding and exclusions.
Evidence standard for this calculation
Check whether each charge is mandatory, when it is paid and whether it reduces proceeds or changes a later payment. Inputs remain in the browser and outputs are rounded for display.
Read the complete methodology →True APR questions before you trust the percentage
What rate is implied by the cash you actually receive?
It is the discount rate that makes the amount received after upfront fees equal the present value of every required payment and recurring fee.
How much do mandatory recurring fees change annualized cost?
Even a small monthly charge raises cost because it is paid repeatedly; the calculator includes each charge in the cash-flow rate before annualizing it.
Fees to classify before entering them
- Which fees are mandatory finance charges
- The lender's statutory APR and payment dates
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Separate the advertised rate from the dollars that leave your account.