Karl&Sam Loan & Payment Calculator

Work out your payment, total interest and payoff date — then see how extra payments save you money. Free, no signup, and nothing you enter ever leaves your device.

Loan details

One-time lump sums

Results

Payment (monthly)
Number of payments
Payoff date
Total interest
Total paid
#DatePaymentPrincipalInterestExtraBalance

100% private: every calculation runs in your browser. No uploads, no tracking. Estimates only — not financial advice.