Mortgage Calculator

How to use this tool

Estimate a conventional fixed-rate mortgage and layer user-entered monthly housing costs without changing loan amortization.

How mortgage payments are calculated

The calculator subtracts the down payment from the home price, then sends the resulting principal, fixed interest rate and term to CorelyUp's shared amortization engine. The scheduled principal-and-interest payment uses the standard fixed-rate formula.

Property tax, homeowners insurance, HOA dues and PMI are added as separate user-entered monthly estimates. These costs do not repay the loan or change its amortization schedule.

Down payment and loan-to-value

A larger down payment reduces the mortgage principal. Loan-to-value, or LTV, is the principal divided by the home price. Some mortgage products may add mortgage-insurance costs at higher LTV levels, but the applicable rules depend on lender, product and country.

Taxes, insurance, HOA, PMI and escrow

Property taxes vary by jurisdiction, insurance varies by property and coverage, and HOA dues vary by community. Enter annual tax and insurance estimates, monthly HOA dues, and an optional annual PMI rate only when relevant.

Some lenders collect taxes and insurance through escrow. This calculator simply divides the entered annual estimates by 12; it does not model escrow timing, shortages or lender rules. PMI terminology is especially associated with U.S. conventional mortgages and should not be treated as universal.

15-year versus 30-year mortgages

A 15-year term generally has a higher monthly principal-and-interest payment, faster payoff and less total interest. A 30-year term generally lowers the monthly payment but extends repayment and usually increases total interest. This is a neutral cost comparison, not a recommendation.

Extra principal and amortization

Recurring extra principal can shorten payoff and reduce future interest when a lender applies it directly to the balance. Taxes, insurance, HOA and PMI are excluded from payoff mathematics. Check the mortgage contract for application rules and prepayment charges.

The yearly table summarizes principal, interest, extra principal and ending balance. The monthly table starts with 12 rows and can expand to the complete estimated schedule.

Interest rate, APR and excluded costs

The entered nominal interest rate drives the payment calculation. APR can include eligible lender fees, so it may differ. This calculator does not calculate APR, closing costs, tax deductions, qualification, affordability, refinancing or country-specific regulation.

Verified mortgage examples

Standard example: a $400,000 home with $80,000 down creates a $320,000 mortgage. At 6% for 30 years, principal and interest are about $1,918.56 per month, with about $370,682.20 total interest before housing costs.

Larger down payment: raising the down payment to $100,000 creates a $300,000 mortgage. At 6% for 30 years, principal and interest are about $1,798.65 per month.

Extra-principal example: adding $250 per month to the $320,000 example reduces estimated payoff from 360 to 269 payments and lowers interest to about $262,066.51, subject to lender rules.

Term comparison: the same $320,000 at 6% over 15 years is about $2,700.34 per month with about $166,061.53 interest, compared with $1,918.56 per month and about $370,682.20 interest over 30 years.

Common mortgage-calculation mistakes

Common mistakes include treating APR as the interest rate, forgetting taxes or insurance, assuming every buyer needs PMI below 20% down, counting HOA as principal, including extra payments in housing costs rather than amortization, and comparing loans only by monthly payment.