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TECHi home

Loan Payment Calculator

Calculate monthly payments, total interest, and see your amortization schedule. Works for mortgages, auto loans, and student loans.

Model year: 2026. Assumptions updated: Sep 24, 2026. Source: Standard amortizing-loan formula. Rate and term are user inputs.. Calculation version: v1.2.

Loan Details

$
$
%
years
Monthly Payment
$1,516.96
Loan Principal
$240,000.00
Total Amount Paid
$546,106.77
Total Interest Paid
$306,106.77

Payment Breakdown

Principal:$240,000
Total Interest:$306,107

Amortization Schedule

Principal Interest

Remaining Balance

How Monthly Loan Payments Are Calculated

Your monthly payment is determined by the standard amortization formula. Each payment consists of two parts: interest on the remaining balance and principal reduction. Early in the loan, most of your payment goes to interest. As the balance decreases, more goes to principal.

M = P × [r(1+r)n] / [(1+r)n – 1]

Where M = monthly payment, P = principal, r = monthly rate (annual/12), n = total months.

15-Year vs. 30-Year Mortgage

A 15-year mortgage has higher monthly payments but dramatically less total interest. On a $240,000 loan at 6.5%, the 30-year payment is about $1,517/month ($306,480 total interest), while the 15-year payment is about $2,091/month ($136,420 total interest) — saving you $170,000 in interest.

How Interest Rates Affect Your Payment

A 1% difference in interest rate on a $300,000 mortgage changes your monthly payment by roughly $199 and your total interest by over $70,000 over 30 years. Even small rate differences matter enormously over the life of a loan.

Assumptions and disclaimer

Calculator outputs are educational estimates, not financial, investment, tax, or legal advice. Results depend on the inputs and assumptions shown on the page and may exclude fees, state rules, market volatility, liquidity, or timing effects. Verify figures with current sources and consult a qualified professional before making decisions.

How to use it

  1. 1Enter price, down payment, and rateThe loan amount is the price minus the down payment.
  2. 2Set the term in yearsA shorter term raises the payment and cuts total interest.
  3. 3Read payment and interestThe schedule shows how much of each year is interest versus principal.

Questions people ask

Is this a full mortgage quote?
No. It models a fixed-rate amortizing loan. It does not include PMI, taxes, insurance, or points.
What if the rate is zero?
The payment is the loan amount split evenly across the months. Interest is zero.