Personal Loan Calculator
Installments, total cost and real rate.
Monthly payment
$362
/ mo
Total paid
$13,015
Total interest
$3,015
Real APR
9.18%
How this tool works
Before signing a personal loan, almost nobody runs the numbers. The bank shows you the monthly payment and it sounds manageable — but the important question is how much you'll pay in total, not how much you pay each month.
This calculator applies the French amortization formula (constant payment) and gives you three things the contract usually hides: the real payment, the total interest accumulated at payoff, and the effective APR — which is almost always higher than the advertised nominal rate due to monthly compounding.
Formula
Payment = (P × i) / (1 − (1 + i)−n) where P is principal, i is monthly rate (annual ÷ 12) and n the term in months. Real APR is ((Total paid / P)12/n − 1) × 100.
How to use it, step by step
- 1
Loan amount
Net amount you receive. If the bank deducts origination fees, subtract them first.
- 2
Annual rate
Always ask for the NOMINAL annual rate in the contract. If they give you APR directly, even better — that already includes fees.
- 3
Term in months
12 / 24 / 36 / 60 are most common. Longer terms lower the payment but explode total interest.
- 4
Compare scenarios
Change the term and watch how total cost shifts. That difference is what the bank charges you for more time.
Use cases
- Compare 2 loan offers with different rates and terms
- Know the real cost before accepting bank pre-approval
- Calculate savings from early payoff
- Evaluate if refinancing at a lower rate is worth it
Common pitfalls
- Confusing monthly rate with annual rate — banks sometimes present it ambiguously
- Forgetting origination, maintenance, mandatory life insurance fees
- Looking only at payment: $200/mo × 60 mo = $12,000 paid, not $10,000
- Assuming pre-approval = best rate: often they offer you the worst one
Frequently asked questions
- What's a reasonable rate in LATAM 2026?
- Argentina: 80-150% annual. Mexico: 25-55%. Colombia: 18-35%. Chile: 12-22%. Brazil: 30-60%. If they quote way above these, it's predatory.
- Should I pay off early?
- Almost always yes — but check the prepayment clause. Some banks charge 1-3% of balance as penalty. If the penalty is less than future interest, pay it down.
- Why is APR higher than nominal rate?
- Because interest compounds monthly. A 24% nominal annual rate with monthly payments gives an APR of ~26.8%. Compound interest math.
- Does it work for a mortgage?
- For quick estimates yes, but mortgages have variable amortization, inflation adjustments and insurance that distort it. Use the dedicated mortgage calculator.