Kalcify
Finance Tool

Loan Calculator

Calculate your monthly loan payment, total interest paid, and total cost of borrowing. View a detailed amortization schedule showing how each payment is split between principal and interest over the life of your loan.

Fixed-rate loan calculation with full amortization breakdown

Calculate Your Loan Payment

The total amount you plan to borrow

The yearly interest rate on your loan

Duration of the loan

Choose years or months

How to Use This Loan Calculator

1

Enter Loan Details

Type your loan amount, annual interest rate, and loan term. Choose whether the term is in years or months.

2

Calculate Payment

Click the calculate button to see your monthly payment, total cost, and total interest over the life of the loan.

3

Review Amortization

Examine the amortization schedule to see how each payment is split between principal and interest. Toggle between yearly and monthly views.

How Loan Amortization Works

M = P * [r(1+r)^n] / [(1+r)^n - 1]

The amortization formula calculates the fixed monthly payment needed to fully repay a loan over a set number of periods at a fixed interest rate. Each payment covers the interest accrued on the remaining balance plus a portion that reduces the principal.

M = Monthly paymentP = Principal (loan amount)r = Monthly interest rate (annual rate / 12 / 100)n = Total number of monthly payments

Key concepts in loan amortization:

  1. Early payments are mostly interest because the balance is highest at the start. As you pay down principal, more of each payment goes to principal.
  2. Shorter terms mean higher monthly payments but significantly less total interest. A 15-year loan typically saves tens of thousands in interest versus a 30-year loan.
  3. Extra payments applied to principal can dramatically reduce total interest and shorten the loan term. Even small additional amounts help.
  4. At 0% interest, the payment is simply the principal divided by the number of months, with no interest cost.

This calculator computes principal and interest (P&I) only. For mortgage loans, your actual payment may also include property taxes, homeowner's insurance, and PMI.

Quick Loan Reference Table

Loan AmountRateTermMonthlyTotal Interest
$10,000.006.5%3 yr$306.49$1,033.64
$25,000.005%5 yr$471.78$3,306.85
$50,000.007%7 yr$754.63$13,389.26
$150,000.006%15 yr$1,265.79$77,841.34
$200,000.006.5%30 yr$1,264.14$255,088.98
$300,000.007%30 yr$1,995.91$418,526.69
$400,000.006.5%30 yr$2,528.27$510,177.95
$500,000.006%30 yr$2,997.75$579,190.95

Fixed-rate loans, principal and interest only

Frequently Asked Questions

How is the monthly loan payment calculated?

The monthly payment is calculated using the standard amortization formula: M = P * [r(1+r)^n] / [(1+r)^n - 1], where P is the loan principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. This ensures each payment covers interest on the remaining balance plus a portion of the principal.

What is an amortization schedule?

An amortization schedule is a table showing each periodic payment on an amortizing loan. Each row breaks down how much of the payment goes toward interest and how much goes toward reducing the principal balance. Early payments are mostly interest, while later payments are mostly principal.

How does the interest rate affect my total loan cost?

Even a small difference in interest rate can significantly affect total cost. For example, on a $200,000 loan over 30 years, a 1% increase in rate (from 6% to 7%) adds roughly $48,000 in total interest over the life of the loan. Always compare rates from multiple lenders to minimize your borrowing cost.

What is the difference between loan term in years vs months?

They are simply different ways to express the same duration. A 30-year mortgage is the same as a 360-month mortgage. Shorter terms mean higher monthly payments but less total interest paid. Longer terms lower monthly payments but increase the total interest cost.

Does this calculator include taxes and insurance?

No, this calculator shows principal and interest (P&I) only. Your actual monthly payment for a mortgage may also include property taxes, homeowner's insurance, and private mortgage insurance (PMI). These additional costs are often collected together in an escrow payment. Use a dedicated mortgage calculator for a full PITI breakdown.

Important Disclaimer

This calculator provides estimates for informational purposes only. Results assume a fixed interest rate and do not include taxes, insurance, PMI, closing costs, or fees. Actual loan terms, rates, and payments may differ based on your credit profile, lender, and loan type. Consult a qualified financial professional or lender for specific loan advice.