Loan Calculator
Monthly payment and total interest on any fixed-rate loan.
Result
Pay $405.53/month for 5 years. Total interest: $4,332.
- Total paid
- $24,332
- Total interest
- $4,332
- Payments
- 60
Inputs
Formula
M = P · r ÷ (1 − (1+r)⁻ⁿ)
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Calcxo gives you the answer plus the reasoning behind it.
Quick answer
Loan Calculator: in one paragraph
A loan calculator turns the amount you borrow, the interest rate, and the length of the loan into a fixed monthly payment — and shows how much of the total you'll spend on interest.
What this calculator does
Enter the loan amount, annual interest rate, and term in years. The calculator returns the monthly payment plus the total interest you'll pay over the life of the loan.
Why people use it
- See the real monthly cost before you sign anything.
- Compare two offers by changing only the rate or the term.
- Understand how much of the total you'll spend on interest, not principal.
- Decide whether a shorter term is worth the higher monthly payment.
A worked loan calculation
A concrete walkthrough you can follow line by line.
You borrow $20,000 at 8% APR over 5 years.
1. Convert annual rate to monthly
8% ÷ 12 = 0.667% per month
2. Count payments
5 years × 12 = 60 monthly payments
3. Apply the amortization formula
M = P · r ÷ (1 − (1+r)⁻ⁿ) ≈ $405.53
Result
Monthly payment ≈ $405.53. Total interest over 5 years ≈ $4,332.
When to use this calculator
- Personal loans, student loans, or any fixed-rate installment loan.
- Comparing offers from different lenders side by side.
- Use the Mortgage or Auto Loan calculator instead when taxes, insurance, or trade-in values are involved.
Common mistakes
- Confusing the interest rate with APR — APR includes some fees, the rate doesn't.
- Comparing only the monthly payment instead of total interest paid.
- Forgetting that a longer term means a smaller payment but more interest overall.
- Ignoring origination fees that lenders deduct from the disbursed amount.
Quick questions
Does this include fees?+
No. The result is principal and interest only. Origination fees, late fees, and insurance are not modelled — add them separately when comparing offers.
Why does total interest jump so much when I extend the term?+
A longer term means more months of interest charges on the remaining balance. Even at the same rate, a 7-year loan costs much more in interest than a 3-year loan.
Learn more
Deeper reads from the Calcxo learn library.
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Revision history2 changes · last on Mar 30, 2026⌄
- ContentExpanded explanation of APR vs nominal interest.
- ReleasedInitial release.