California Mortgage Calculator

Principal and interest use the amortizing loan formula M = P × r ÷ (1 − (1 + r)⁻ⁿ), where P is the loan amount, r the monthly interest rate and n the total number of monthly payments. Property tax, homeowners insurance and any HOA fee are then divided by twelve and added on top, since those are pass-through costs that do not accrue interest.

Most monthly mortgage payments include four things, known together as PITI: principal, interest, property taxes and homeowners insurance. Taxes and insurance are usually collected by the lender into an escrow account and paid on your behalf. If the property is in a homeowners association you also pay an HOA fee, though that normally goes directly to the association rather than through your lender. Private mortgage insurance is added when the down payment is under 20%.

A common guideline is that total housing costs stay under 28% of gross monthly income, and that all debt payments together stay under 36%. On a $120,000 salary that is roughly $2,800 a month for housing and $3,600 for all debts combined. The affordability calculator works this out from your income, existing debts and down payment.

Twenty percent is the threshold that removes private mortgage insurance on a conventional loan, which typically saves 0.5%–1.5% of the loan amount every year. It is not a requirement: conventional loans can go to 3%, FHA loans to 3.5%, and VA and USDA loans to zero for those who qualify. A smaller down payment means a larger loan, a higher payment and more interest overall.

Cheaper each month, far more expensive in total. A $320,000 loan at 6.5% costs about $2,023 a month over 30 years and roughly $408,000 in interest. The same loan over 15 years costs about $2,787 a month but only around $182,000 in interest. The 15-year term also usually carries a slightly lower rate. Which is right depends on whether the monthly headroom is worth more to you than the lifetime saving.

No. Private mortgage insurance depends on your credit score, loan type and loan-to-value ratio, and it stops once you build enough equity, so including a single estimate would be misleading. If your down payment is below 20%, budget an extra 0.5%–1.5% of the loan amount per year on top of the figures shown here.

The effective statewide rate is around 0.71% of assessed value. Proposition 13 sets a base rate near 1% and limits annual assessment increases to 2%, which is why long-standing owners often pay much less than recent buyers on comparable homes. Your assessment resets to the purchase price when you buy.

Wildfire risk has led several large insurers to restrict or stop writing new policies in higher-risk areas, reducing competition and raising premiums. The statewide average is around $1,800 a year, but homes in fire-prone counties can pay several times that. The California FAIR Plan provides last-resort coverage where the private market will not.

Mello-Roos is a special tax district used to fund infrastructure in newer developments. Where it applies it is charged on top of ordinary property tax and can add several hundred dollars a month for twenty to forty years. It is disclosed during the purchase process — ask specifically, because it is not part of the headline tax rate.