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Mortgage Calculator

What Is a Mortgage?

A mortgage is a loan used to purchase real estate, where the property itself serves as collateral. The borrower agrees to repay the loan over a set period (typically 15 or 30 years) through monthly payments that include both principal and interest. In the United States, the 30-year fixed-rate mortgage is the most common type, representing roughly 70–90% of all home loans. Your monthly payment is determined by the loan amount, interest rate, and term length.

Understanding PITI: The Full Monthly Payment

Your true monthly mortgage payment is more than just principal and interest. Lenders and financial advisors use the acronym PITI — Principal, Interest, Taxes, and Insurance — to describe the complete monthly housing cost. Property taxes are assessed annually by your local government (U.S. average: ~1.1% of home value). Homeowners insurance protects your property against damage (average: $1,500–$3,000/year). If your down payment is less than 20%, you'll also pay Private Mortgage Insurance (PMI), which protects the lender — not you — if you default.

How Much Should You Put Down?

The traditional advice is 20% down to avoid PMI and secure the best interest rates. However, many loan programs accept much less: conventional loans allow as low as 3%, FHA loans require 3.5%, and VA/USDA loans may require 0%. A larger down payment reduces your monthly payment, total interest paid, and the risk of being 'underwater' (owing more than the home is worth). Use the 28/36 rule as a guideline: spend no more than 28% of gross monthly income on housing costs, and no more than 36% on total debt including housing.

15-Year vs. 30-Year Mortgage

A 30-year mortgage offers lower monthly payments but costs significantly more in total interest. For example, a $300,000 loan at 6.5% costs about $1,896/month over 30 years (total interest: $382,633) versus $2,613/month over 15 years (total interest: $170,269). That's a $212,364 difference in interest. The 15-year term also typically comes with a lower interest rate (0.5–0.75% less). Choose 30 years if you need payment flexibility; choose 15 years if you can handle higher payments and want to build equity faster.

How Amortization Works

Early in your mortgage, most of each payment goes toward interest rather than reducing your loan balance. On a 30-year, $300,000 loan at 6.5%, your first payment allocates $1,625 to interest and only $271 to principal. By year 15, it flips — $963 goes to principal and $933 to interest. This is why extra payments in the early years are so powerful: every additional dollar goes directly to principal, saving you multiple dollars in future interest and potentially shaving years off your loan.

Frequently Asked Questions

How much house can I afford?

Use the 28/36 rule: your monthly housing costs (PITI + HOA) should not exceed 28% of your gross monthly income, and your total debt payments should stay below 36%. For example, if you earn $6,000/month gross, aim for a maximum housing payment of $1,680. Factor in property taxes, insurance, and PMI — not just the loan payment. Also consider closing costs (2–5% of home price), moving expenses, and an emergency fund covering 3–6 months of payments.

What is PMI and how do I avoid it?

Private Mortgage Insurance (PMI) protects the lender — not you — if you default on the loan. It's typically required when your down payment is less than 20% of the home price. PMI costs 0.3–1.5% of the loan amount annually, adding $100–$300/month on a typical loan. To avoid PMI: put 20% or more down, use a piggyback loan (80/10/10), or choose a VA loan (no PMI required). If you already have PMI, request removal once your loan-to-value ratio drops below 80% — lenders must automatically cancel it at 78% LTV.

Should I choose a fixed-rate or adjustable-rate mortgage?

A fixed-rate mortgage locks your interest rate for the entire loan term, providing predictable payments. An adjustable-rate mortgage (ARM) starts with a lower rate that adjusts after an initial period (typically 5, 7, or 10 years). ARMs can save money if you plan to sell or refinance before the adjustment period, but carry risk if rates rise. In a high-rate environment, ARMs may offer meaningful initial savings. In a low-rate environment, locking in a fixed rate provides long-term security.

What fees should I expect at closing?

Closing costs typically run 2–5% of the home price and include: lender origination fees (0.5–1%), appraisal ($300–$600), title search and insurance ($500–$3,000), attorney fees, recording fees, and prepaid items (property tax and insurance escrow). On a $350,000 home, expect $7,000–$17,500 in closing costs. Some costs are negotiable, and sellers sometimes contribute toward closing costs as part of the deal. Always request a Loan Estimate from your lender for a detailed breakdown.

How does property tax affect my monthly payment?

Property taxes are assessed annually by your local government based on your home's assessed value. The U.S. average effective rate is about 1.1%, but it varies dramatically by state — from 0.27% in Hawaii to 2.47% in New Jersey. On a $350,000 home at 1.2%, that's $4,200/year or $350/month added to your mortgage payment. Most lenders require an escrow account where 1/12 of your annual tax bill is collected each month and paid on your behalf.

Is it worth paying extra toward my mortgage?

Extra payments can save substantial interest and shorten your loan term. On a $300,000 loan at 6.5% over 30 years, paying just $200 extra per month saves about $115,000 in interest and pays off the loan 7 years early. Even one extra payment per year (or biweekly payments) can cut 4–6 years off a 30-year mortgage. However, prioritize high-interest debt and retirement savings first — if your mortgage rate is 3–4%, investing the extra money may yield better returns.

What is an amortization schedule?

An amortization schedule is a month-by-month table showing exactly how each payment is split between principal and interest, plus the remaining loan balance. It reveals that early payments are mostly interest (often 80%+ in year one), gradually shifting toward principal over time. Reviewing your amortization schedule helps you understand when you'll reach 20% equity (to remove PMI), how extra payments impact your payoff timeline, and the true cost of your loan over its lifetime.

Can I use this calculator for mortgages outside the U.S.?

Yes — the core principal and interest calculation works universally for any fixed-rate amortizing loan. Select your local currency from the dropdown to see results in your currency. Note that property tax rates, insurance costs, and PMI rules vary by country. In many countries outside the U.S., mortgage terms, regulations, and typical structures differ (e.g., variable rates are more common in the UK and Australia). Adjust the inputs to match your local conditions for the most accurate estimate.