Calculators
Start with payoff to estimate a timeline, extra payment to compare a recurring increase, or target date to find a monthly budget. Card and loan tools explain the assumptions relevant to those debts. Each tool models one balance; currency selection changes display units, not exchange rates.
How this works
Each monthly period starts with interest on the remaining balance: balance × nominal annual rate / 1200 when the rate is entered as a percentage. Interest rounds half-up to cents, then the regular payment is applied before the monthly extra. The annual rate is fixed; there is no new borrowing. Balances and totals accumulate in integer cents.
Worked example
With USD 1,000, fixed 12% nominal annual rate, USD 100 monthly, no extra and a 31 January 2026 start, the model finishes in 11 payments on 31 December 2026. Total interest is USD 58.98; the final payment is USD 58.98. No fees or new borrowing are assumed.
Where lenders may differ
Daily interest, fees, changing rates, promotional periods, and payment timing can change the result. This is not a payoff quote. Inputs are limited to 1 billion per amount, 0–100% nominal annual rate, and 1,200 months. The target mode verifies its payment with the same monthly schedule.
Simple, private, explainable
No account or bank connection is required. The published monthly model uses a fixed annual rate and rounded interest; saved plans stay in this browser. Daily interest, fees and changing rates are outside the model. Calcuti is for planning and education, not personal financial advice or a lender payoff quote. Contact us about errors or suggestions.