A free online installment interest-rate calculator: enter the loan principal, the amount paid per period, the number of periods and any one-off upfront fee to solve the real annualized rate (IRR). It also shows the monthly rate, nominal annual rate, total repayment and total interest — ideal for checking the true cost of installment loans and consumer credit.
Optional, e.g. a one-off fee deducted at disbursement
Monthly rate
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Nominal annual rate
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Effective annual rate (IRR)
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Total repayment
—CNY
Total interest
—CNY
The effective annual rate uses the internal rate of return (IRR) compounding convention: with net proceeds as present value and each repayment as cash flow, solve for the monthly rate r where net present value is zero; annual = (1 + r)^12 − 1. Nominal annual = monthly rate × 12. Results are for reference only.