Mortgage Calculator
Work out the full monthly cost of a home: principal and interest, property taxes, insurance and HOA dues, with the balance drawn year by year. A repayment or interest-only switch is built in.
What a mortgage really costs each month
The bank quotes you principal and interest; the house charges you more. Property taxes, homeowners insurance and HOA dues ride along every month, and on many homes they add a third or more to the bank's figure. This calculator assembles the whole bill — lenders call it PITI plus dues — so the number you budget against is the number that leaves your account.
Monthly P&I = loan × r ÷ (1 − (1 + r)−n), with r = annual rate ÷ 12 and n = months in the term
Example: a $300,000 loan at 6% for 30 years gives principal and interest of $1,798.65. Add $300 a month of property taxes, $150 of insurance and no HOA dues, and the true monthly cost is $2,248.65.
Repayment vs interest-only
A repayment mortgage (the US standard, and what UK lenders mean by the word) slices every payment into interest plus a little principal, clearing the debt exactly at the term's end. An interest-only mortgage pays only the interest for a set period — the payment is lighter, the balance never moves, and either a repayment phase or a lump sum must follow. The switch in the form runs both patterns on your figures.
How this is calculated
The loan is the home price minus the down payment. Monthly principal and interest use the standard amortization formula with the nominal annual rate divided by 12 and payments at month end; the balance chart applies the same payment month after month. Taxes are your annual figure divided by 12, insurance likewise, HOA dues are taken as monthly.
On the interest-only setting, payments during the interest-only years are simply balance × rate ÷ 12, and the remaining years amortize the untouched balance over what is left of the term. Nothing is rounded until display.
Frequently asked questions
What is included in a mortgage payment?
Four things, usually: principal (repaying the loan), interest, property taxes and homeowners insurance — PITI. Many loans also carry HOA dues, and loans under 20% down typically add PMI. This calculator shows each part separately.
How much of my first payment is interest?
On a $300,000 loan at 6%, the first month's interest is exactly $1,500 of the $1,798.65 payment — over 83%. The split inverts slowly over the years; by the final year almost every dollar is principal.
Does a bigger down payment change the rate or just the loan?
Both can change: a larger down payment shrinks the loan directly, and at certain thresholds (notably 20% down) it also removes PMI and can improve the rate a lender offers.
Repayment or interest-only — which is safer?
Repayment, for almost every household: the debt is guaranteed gone at the term's end. Interest-only only works with a disciplined, separate plan to clear the capital, and lenders price and scrutinize it accordingly.
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