Mortgage Calculator
Calculate monthly mortgage payment, total interest, and a full amortization schedule in real time.
Loan Inputs
= $80,000.00 (20.0% of home price)
Results
Monthly payment (P&I)
$2,022.62
Loan amount: $320,000.00
Loan amount
$320,000.00
Total interest paid
$408,142.36
Total cost of loan
$728,142.36
Principal vs Interest by Year
Amortization Table (Annual)
| Year | Principal Paid | Interest Paid | Remaining Balance |
|---|---|---|---|
| 1 | $3,576.72 | $20,694.69 | $316,423.28 |
| 2 | $3,816.26 | $20,455.15 | $312,607.02 |
| 3 | $4,071.84 | $20,199.57 | $308,535.17 |
| 4 | $4,344.54 | $19,926.87 | $304,190.63 |
| 5 | $4,635.50 | $19,635.91 | $299,555.13 |
| 6 | $4,945.95 | $19,325.46 | $294,609.18 |
| 7 | $5,277.19 | $18,994.22 | $289,331.98 |
| 8 | $5,630.62 | $18,640.80 | $283,701.37 |
| 9 | $6,007.71 | $18,263.70 | $277,693.66 |
| 10 | $6,410.06 | $17,861.36 | $271,283.60 |
| 11 | $6,839.35 | $17,432.06 | $264,444.26 |
| 12 | $7,297.39 | $16,974.02 | $257,146.86 |
| 13 | $7,786.11 | $16,485.30 | $249,360.75 |
| 14 | $8,307.56 | $15,963.85 | $241,053.19 |
| 15 | $8,863.94 | $15,407.48 | $232,189.25 |
| 16 | $9,457.57 | $14,813.84 | $222,731.68 |
| 17 | $10,090.96 | $14,180.45 | $212,640.72 |
| 18 | $10,766.77 | $13,504.64 | $201,873.95 |
| 19 | $11,487.84 | $12,783.57 | $190,386.11 |
| 20 | $12,257.20 | $12,014.21 | $178,128.90 |
| 21 | $13,078.09 | $11,193.32 | $165,050.81 |
| 22 | $13,953.96 | $10,317.46 | $151,096.86 |
| 23 | $14,888.48 | $9,382.93 | $136,208.38 |
| 24 | $15,885.59 | $8,385.83 | $120,322.79 |
| 25 | $16,949.47 | $7,321.94 | $103,373.32 |
| 26 | $18,084.61 | $6,186.80 | $85,288.71 |
| 27 | $19,295.77 | $4,975.64 | $65,992.94 |
| 28 | $20,588.05 | $3,683.37 | $45,404.89 |
| 29 | $21,966.86 | $2,304.55 | $23,438.03 |
| 30 | $23,438.03 | $833.39 | $0.00 |
How to Use the Mortgage Calculator
A mortgage calculator helps you estimate what buying a home will cost each month before you apply with a lender. By combining home price, down payment, loan term, and interest rate, this tool shows your estimated monthly principal and interest payment instantly. The numbers update in real time so you can compare scenarios as you type.
Understanding the Formula
The standard mortgage payment formula is M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan principal (home price minus down payment), r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. This formula ensures that each payment covers the interest due while gradually reducing the principal.
Reading the Amortization Schedule
The amortization schedule gives a year-by-year breakdown of how each payment is split between principal and interest. Early in the loan, a larger share goes to interest. Over time, more of each payment reduces your actual balance. This view is especially useful when deciding between a 15-year and 30-year loan or evaluating whether a larger down payment is worth it.
15 vs 30-Year Mortgage
On a $300,000 loan at 6.5%, a 30-year term results in a monthly payment of about $1,896 and total interest of approximately $382,600. A 15-year term raises the monthly payment to about $2,613 but slashes total interest to around $170,300 — saving over $212,000. If you can afford the higher payment, the 15-year loan builds equity much faster and dramatically reduces total borrowing cost.
Beyond Principal and Interest
Use this calculator to plan affordability, compare refinance options, and understand total borrowing cost. Remember that real monthly housing costs also include property taxes, homeowners insurance, HOA dues, and possibly mortgage insurance. For final loan details, confirm terms directly with your lender.
Tips for Shopping Mortgages
Test several interest rates and down payment amounts to understand how sensitive your payment is to market conditions. A one-percentage-point difference in interest rate can change your monthly payment by $150–$250 on a $300,000 loan and add tens of thousands of dollars to total interest paid. Getting pre-approved by multiple lenders allows you to compare real rates, not just estimates.