Loan Calculator

Calculate loan payments and total cost

Disclaimer

This tool provides estimates for educational purposes only and is not financial advice. Actual loan terms, rates, and payments vary by lender, credit score, and other factors. Consult a licensed financial advisor before making borrowing decisions.

How this is calculated

Loan payments use the standard amortization formula:

  1. Monthly interest rate = annual rate ÷ 12.
  2. Monthly payment = principal × [r(1+r)^n] ÷ [(1+r)^n − 1], where r = monthly rate, n = total months.
  3. Total payment = monthly payment × number of months.
  4. Total interest = total payment − principal.
  5. Each month: interest portion = remaining balance × monthly rate; principal portion = payment − interest.

Sources

Reviewed against 2026 figures · Last updated June 2026

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zhisan
Independent Developer

Full-stack developer passionate about building useful tools for the developer community. Creates free, privacy-focused web applications that solve everyday coding problems.

What is Loan Calculator?

A loan calculator helps you understand the true cost of borrowing money using the standard amortization formula. Whether you are considering a personal loan, auto loan, student loan, or managing credit card debt, this tool shows your monthly payment, total interest, and how payments reduce your balance over time. The key insight of amortization is that early payments are mostly interest, while later payments are mostly principal. For a $25,000 personal loan at 8.5% over 5 years, your monthly payment is approximately $513. Over the life of the loan, you pay $5,780 in interest — meaning the true cost is $30,780 for borrowing $25,000. Understanding APR vs. interest rate is critical: APR includes fees and closing costs, giving a more accurate picture of the loan's true cost. A loan with a 7% interest rate but high origination fees may have a 8.5% APR, making it more expensive than a 8% loan with no fees.

How to Use

  1. Enter the total loan amount you want to borrow.
  2. Input the annual interest rate (APR) offered by your lender.
  3. Select the loan type to see typical terms for that category.
  4. Set the loan term in years and optionally add extra months.
  5. Click Calculate to see your complete payment breakdown.
  6. Review the payment schedule to understand how your loan amortizes.

Why Use This Tool?

Know exactly how much you'll pay monthly before signing a loan agreement
See the total interest cost over the life of the loan
Compare different loan terms to find the best option
Understand the interest vs principal breakdown of each payment
Plan your budget with accurate payment forecasts
Make extra payments strategically by seeing amortization impact

Tips & Best Practices

  • Shorter loan terms mean higher payments but significantly less total interest — a 3-year term on $25,000 at 8% saves ~$2,000 vs. a 5-year term
  • APR includes fees and gives a more accurate cost than the stated interest rate alone
  • Extra payments toward principal can save hundreds or thousands in interest — even $50/month extra makes a difference
  • Compare offers from multiple lenders — rates can vary by several percentage points for the same borrower
  • Consider total cost (not just monthly payment) when choosing a loan term
  • Auto loans often have lower rates than personal loans because they're secured by the vehicle

Frequently Asked Questions

What's the difference between interest rate and APR?

The interest rate is the cost of borrowing the principal. APR (Annual Percentage Rate) includes the interest rate plus other fees and costs (origination fees, closing costs), giving you a more complete picture of the loan's true cost. Under the Truth in Lending Act (TILA), lenders must disclose APR. Always compare APRs when shopping for loans.

How do loan types affect my terms?

Auto loans are secured by the vehicle and typically have lower rates (4-8%). Personal loans are unsecured and have higher rates (6-36%). Student loans often have special terms and lower rates. Credit cards have the highest rates (15-25%+) and should be paid quickly to minimize interest charges.

Should I choose a longer or shorter loan term?

Shorter terms have higher monthly payments but save significantly on total interest. For a $25,000 loan at 8%, a 3-year term saves about $2,000 in interest vs a 5-year term. Choose based on your budget comfort level and total cost goals.

How can I reduce my total interest paid?

Make extra payments toward principal (specify this to your lender), choose a shorter term, find a lower rate by comparing lenders, and avoid extending terms when refinancing. Even $50 extra per month can save hundreds over the loan.

What does this calculator not cover?

This calculator provides basic amortization estimates. It does not cover: variable-rate loans (ARMs), prepayment penalties, origination fees and closing costs, loan insurance (PMI, MIP), balloon payments, or the tax deductibility of loan interest (e.g., mortgage interest deduction under IRC § 163(h)). This is an educational tool — consult a financial advisor for personalized borrowing advice.

Real-world Examples

$25,000 personal loan at 8.5% for 5 years

A borrower takes a $25,000 personal loan to consolidate credit card debt at 8.5% APR over 5 years.

Input
Loan amount:          $25,000
Annual rate:          8.5%
Term:                 5 years (60 months)

Monthly rate:         8.5% ÷ 12 = 0.7083%
Monthly payment:      $25,000 × [0.007083 × (1.007083)^60]
                      ÷ [(1.007083)^60 − 1] = $513.03
Output
Monthly payment:       $513
Total paid:            $30,782
Total interest:        $5,782 (23.1% of principal)

Year 1: ~$2,040 interest, ~$4,116 principal
Year 5: ~$440 interest, ~$5,716 principal

Compared to credit card at 22%:
$25,000 at 22% for 5 years = $692/month
Total interest: $16,520 — saving $10,738!

Related Tools

Data sources: Amortization formula: standard financial mathematics. Rate ranges: Federal Reserve G.19 Consumer Credit report and CFPB data. APR disclosure: Truth in Lending Act (TILA), 15 USC § 1601. This calculator is maintained by Zhisan. Last reviewed 2026. This tool is for informational and educational purposes only and does not constitute financial advice. Consult a licensed financial advisor for personalized borrowing advice.