Quick guide
How to use this calculator
- Enter the purchase, checkout payment, fees, and evenly spaced later instalments from one plan.
- Keep checkout and later-payment timing aligned with the visible labels.
- Use the total and annualized estimate only within the stated exclusions.
Calculation method
Calculation method
Total paid = upfront payment + upfront fee + later instalment count × (instalment + per-instalment fee). The annualized estimate solves the equal-period cash flows, then scales the periodic rate by 365/interval days.
Entered amounts use exact fixed-decimal arithmetic. The periodic rate reuses the bounded non-regulatory cash-flow solver and is annualized only after solving the entered interval.
Worked example
Worked example
A 400 purchase with 100 at checkout and three later 100 instalments every 14 days has no entered fees, total paid of 400, and a 0% cash-flow rate.
Total paid = upfront payment + upfront fee + later instalment count × (instalment + per-instalment fee). The annualized estimate solves the equal-period cash flows, then scales the periodic rate by 365/interval days.
Supported inputs
Precision and limits
Visible input limits
Amounts are capped at 1e12, later instalments at 1,200, intervals at 365 days, annualized estimates at 1000%, and fixed decimals at 12 places.
Estimate, not approval or advice
The result does not determine affordability, eligibility, product safety, credit reporting, disputes, refunds, or the consequences of a missed payment.
International scope
No currency, country, lender policy, tax, credit-reporting rule, consumer protection, or regulated APR method is assumed.
Calculator-specific assumptions
This models evenly spaced entered cash flows, not affordability, approval, lateness, refunds, reporting, or legal disclosures. Late, overdraft, insufficient-funds, merchant, and unentered fees are excluded. The annualized figure is a mathematical comparison estimate, not a regulated APR.