Mortgage Calculator

This is the main OverCalculator mortgage payment page: it starts with a home price and down payment, builds the loan amount, computes the fixed principal-and-interest payment, and then layers in the monthly ownership costs that are entered directly in the inputs. Use it when you want one practical housing-payment estimate rather than a narrow principal-only answer or a full line-by-line amortization schedule.

The page intentionally sits between the sibling tools. The simple mortgage calculator is for a clean loan amount, rate, and term with no escrow costs. The mortgage calculator with taxes and insurance is the PITI-focused version that starts property tax from a percentage rate. The mortgage amortization calculator inspects a specific payment number and balance. The mortgage rate calculator focuses on how rate, points, and fees affect payment and scenario effective-rate comparisons.

What the inputs mean

Enter the home price first. Then choose whether the down payment is entered as a percentage or a dollar amount. The calculator subtracts that down payment from the home price to get the mortgage principal. The annual interest rate is converted to a monthly rate, and the term in years is rounded to a whole number of months.

Property tax and insurance on this page are yearly dollar inputs, not percentages. If you expect 4,800 dollars of annual property tax, enter 4,800 and the calculator uses 400 dollars per month. If insurance is 1,800 dollars per year, it uses 150 dollars per month. HOA fees are already monthly. PMI is optional; when it is switched on and the loan is more than 80 percent of the home price, the calculator applies the annual PMI rate you enter. The 0.5 percent default is adjustable and is only a scenario assumption, not a quote.

The extra payment field is used to simulate faster payoff. It is not added to the headline monthly payment output. That means a 100 dollar extra payment reduces the interest and payoff time in the amortization loop, but your real monthly cash outflow would be the displayed regular payment plus that extra 100 dollars.

Calculation

For loan principal P, monthly interest rate r, and n monthly payments, the standard fixed-rate amortized-payment formula is:

$\text{M} = P \frac{r(1+r)^n}{(1+r)^n-1}$

When the interest rate is zero, the calculator divides the loan amount by the number of months instead. After the principal-and-interest payment is found, monthly tax, monthly insurance, PMI, and HOA dues are added:

$\text{monthly estimate} = \text{principal and interest} + \text{tax} + \text{insurance} + \text{PMI} + \text{HOA}$

Checking a mortgage scenario

Suppose the home price is 360,000 dollars, the down payment is 20 percent, the interest rate is 6.5 percent, the term is 30 years, and all tax, insurance, HOA, and extra-payment inputs are left at zero. The down payment is 72,000 dollars, so the loan amount is 288,000 dollars. The monthly rate is 0.065 divided by 12, or about 0.0054167, and the number of payments is 360.

Using the formula above, the principal-and-interest payment is 1,820.36 dollars per month. Because the down payment is exactly 20 percent, the loan-to-value ratio is 80 percent and PMI is not added. With no yearly tax, no yearly insurance, no HOA dues, and no extra monthly payment, the estimated monthly payment is also 1,820.36 dollars. The amortization loop totals about 367,329 dollars of interest over the scheduled 30 years, and payoff time stays at 30 years.

Now change only the yearly tax to 4,800 dollars and yearly insurance to 1,800 dollars. The calculator adds 400 dollars of tax and 150 dollars of insurance, so the regular monthly estimate becomes 2,370.36 dollars. Those escrow-style amounts do not reduce principal; they are ownership costs collected alongside the loan payment.

Amortization, PITI, and escrow in plain English

Amortization means a level payment is split differently over time. Early in a mortgage, the balance is large, so interest consumes a bigger share of the payment. Later, the balance has fallen, so more of the same payment goes to principal. That is why two loans with the same monthly payment can have very different total interest if one has a shorter term or a lower rate.

PITI stands for principal, interest, taxes, and insurance. This page can approximate PITI when you enter yearly tax and yearly insurance amounts. PMI and HOA dues are related monthly housing costs, but they are not the same thing as principal. PMI protects the lender on certain low-down-payment loans, and HOA dues pay an association. Escrow is the lender-managed account that often collects tax and insurance monthly and pays the bills when they come due. The calculator does not model escrow shortages, cushions, reassessments, or annual insurance changes.

Rate context and planning tips

Mortgage rates move with market conditions, lender pricing, loan type, credit profile, points, and lock timing. A small rate change can have a large effect because it is applied for hundreds of payments. To isolate that effect, open the mortgage rate calculator and compare the same loan balance at nearby rates. To estimate how much cash you need upfront, use the down payment calculator. To test whether the payment fits your income, compare the result with the debt-to-income calculator or the home affordability calculator.

Practical checks: keep taxes and insurance realistic for the specific property, not just a national average; include HOA dues before comparing condos with detached homes; remember that maintenance and utilities are outside the calculator; and treat discount points as a tradeoff between cash now and payment later. This calculator is informational, not financial advice, and it cannot replace a lender’s loan estimate or a housing counselor’s review.

Method scope and source version

Jurisdiction-neutral loan mathematics; lender contracts, disclosures, taxes, insurance, PMI, and compounding conventions vary. Evergreen method only; defaults/examples must not be represented as current market, legal, tax, or institutional data. The sources below support the stated method and definitions; they do not supply a live rate, quote, legal conclusion, lender offer, or institution-specific policy.

Sources

• Consumer Financial Protection Bureau, Loan Estimate explainer — official explanation of loan terms, projected payments, and closing-cost disclosures.
• Consumer Financial Protection Bureau, Explore interest rates — rate-shopping context and borrower-specific mortgage assumptions.
• Freddie Mac, Primary Mortgage Market Survey — weekly mortgage-rate survey used for market context.
• HUD, Buying a home — homebuying and housing-counseling resources.