A mortgage payment is calculated from the loan amount, interest rate, and term using the standard amortization formula. For a $300,000 loan at 6.5% over 30 years, the principal-and-interest payment is about $1,896 per month. Enter your own numbers above to estimate the monthly payment, total interest, and full amortization schedule. Property taxes and insurance are additional.
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Payment
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Disclaimer: This calculator provides estimates for informational purposes only and does not constitute financial advice. Actual results may vary based on lender terms, tax implications, fees, and market conditions. Consult a licensed financial advisor or qualified professional before making financial decisions.
How to Use This Mortgage Calculator
To use the mortgage calculator, enter the home price, down payment, interest rate, loan term, and any extra monthly payments. Click 'Calculate' to see your monthly payment, total interest, and amortization schedule.
Understanding Your Mortgage Payment
Your monthly mortgage payment includes both principal (the amount that reduces your loan balance) and interest (the cost of borrowing). In the early years of your mortgage, most of your payment goes toward interest. Over time, the balance shifts toward principal, a process known as amortization.
The Mortgage Payment Formula
The calculator uses the standard amortization formula: M = P × [r(1+r) n ] / [(1+r) n - 1], where M is the monthly payment, P is the principal (loan amount), r is the monthly interest rate, and n is the total number of payments.
Practical Tips, Edge Cases, and Limitations
A 30-year mortgage has lower monthly payments but significantly more total interest. A 15-year mortgage has higher monthly payments but saves tens of thousands in interest. Making extra payments can reduce total interest and shorten the loan term.
Frequently Asked Questions
The calculator uses the standard amortization formula: M = P × [r(1+r) n ] / [(1+r) n - 1], where M is the monthly payment, P is the principal (loan amount), r is the monthly interest rate, and n is the total number of payments.
Your monthly mortgage payment consists of principal (the amount that reduces your loan balance) and interest (the cost of borrowing).
Consider your income, expenses, and debt when determining how much house you can afford.
Yes, making extra payments toward your mortgage principal can dramatically reduce the total interest paid and shorten your loan term.
PMI (Private Mortgage Insurance) is typically required for loans with a down payment less than 20%.
This mortgage calculator computes your full monthly PITI payment — principal, interest, property taxes, homeowners insurance, and PMI — using the standard amortization formula. Enter your loan details above; the sections below explain exactly how each figure is derived, what affects your rate, and how FHA and conventional loans compare side by side.
How Monthly Mortgage Payment Is Calculated
The Standard Monthly Payment Formula
Every fixed-rate mortgage payment is computed using the standard amortization formula:
M = P × [r(1+r)^n] / [(1+r)^n − 1]
This formula produces the constant monthly payment that fully retires the loan over n months — no balloon, no residual balance. Fannie Mae and Freddie Mac both require lenders to apply this amortization model when underwriting conforming loans, ensuring the payment schedule disclosed on your Loan Estimate matches what you actually owe each month.
Defining Each Variable: P, r, and n
P is the principal — the loan amount after subtracting your down payment from the purchase price. r is the periodic (monthly) interest rate. n is the total number of monthly payments: 360 for a 30-year term, 324 for 27 years, 240 for 20 years, and so on.
How Annual Rate Converts to Monthly Rate
Mortgage rates are quoted annually but payments are monthly, so the annual rate must be divided by 12. A 6.42% annual rate becomes r = 6.42 ÷ 12 ÷ 100 = 0.00535 per month. This formula covers only principal and interest (P&I). Property taxes, homeowners insurance, and private mortgage insurance are calculated separately and added to arrive at the full PITI payment that lenders actually collect each month.
Worked Example: $357,400 Home at 6.42% Over 27 Years
Home price
$357,400
Down payment
12% — $42,888
Loan amount (P)
$314,512
Annual interest rate
6.42%
Loan term
27 years (324 monthly payments)
Property tax
$187/month
Homeowners insurance
$125/month
Annual PMI rate
0.68% of loan balance
Step 1 — Establish Loan Amount After Down Payment
$357,400 × 12% = $42,888 down. Loan amount P = $357,400 − $42,888 = $314,512. The loan-to-value ratio is $314,512 ÷ $357,400 = 88.0%, which exceeds the 80% threshold, so PMI applies on a conventional loan.
Step 2 — Compute Monthly P&I Payment
Convert the annual rate: r = 6.42% ÷ 12 = 0.535% = 0.00535. Total payments: n = 27 × 12 = 324.
$2,048 (P&I) + $178 (PMI) + $187 (property tax) + $125 (homeowners insurance) = $2,538/month estimated total PITI. PMI stays on the bill until the loan balance drops below $285,920 (80% of the $357,400 appraised value), which takes roughly 9–10 years at the standard amortization pace without extra payments.
Understanding Principal, Interest, Taxes, and Insurance (PITI)
Principal and Interest (PI)
The P&I portion is driven purely by the amortization formula. Principal reduces your balance; interest compensates the lender for the outstanding debt. Early payments are heavily weighted toward interest — on a $314,512 loan at 6.42%, month 1 interest alone is $314,512 × 0.00535 = $1,683, leaving only $365 toward principal paydown.
Property Taxes and Escrow
Most lenders require an escrow account funded by collecting one-twelfth of your annual property tax and insurance premium each month alongside the P&I payment. This protects the lender's collateral from tax liens and keeps the property insured. Escrow balances can increase year over year when the county reassesses values — budget for an annual adjustment of 2–5% on the tax portion.
Homeowners Insurance
Lenders require homeowners insurance for the life of the loan. National average premiums run roughly $1,200–$2,000/year, but coastal or high-risk-zone properties can cost significantly more. The $125/month figure in this example ($1,500/year) sits near the national median. Flood or earthquake coverage, if required by your lender or local regulation, would be added separately.
Private Mortgage Insurance (PMI)
Conventional lenders require PMI any time the loan-to-value ratio exceeds 80% — meaning a down payment below 20%. PMI rates range from approximately 0.20% to 1.50% of the loan balance annually, depending on your credit score, LTV, and loan type. At 0.68% on $314,512, the annual cost is $2,139, or $178/month. Under the Homeowners Protection Act of 1998, you can request PMI cancellation once your balance reaches 80% of the original appraised value; servicers must automatically cancel it at 78% LTV. FHA loans carry a Mortgage Insurance Premium (MIP) instead: an upfront charge of 1.75% of the loan amount plus an annual MIP of 0.85% per HUD Handbook 4000.1 — and for loans with LTV above 90% at origination, that annual MIP remains for the life of the loan.
Amortization Schedule Explained
How Amortization Works Month by Month
Each monthly payment is fixed, but the split between interest and principal changes every month. Interest is calculated on the current outstanding balance, so as the balance falls, a slightly larger slice of the fixed payment chips away at principal. In month 1, $1,683 goes to interest and $365 goes to principal. By month 50, the interest portion has fallen to roughly $1,570 and the principal portion has risen to about $478 — a gradual shift that accelerates as the balance shrinks.
Early vs. Late Payments: Where Your Money Goes
The crossover point — where the monthly principal payment finally exceeds the interest charge — occurs around month 194 (approximately year 16) on this $314,512 loan at 6.42%. For the first sixteen years the majority of each payment is interest. Total interest paid over all 324 payments works out to approximately $2,048 × 324 − $314,512 = $349,040 — meaning total dollars out exceed twice the original loan amount if you hold to term. For a full month-by-month breakdown, use the full amortization schedule calculator.
The Cost of Extra Principal Payments
Making even one additional principal-only payment in month 1 eliminates the interest that would have accrued on that extra amount for the remaining life of the loan. An extra $2,048 applied to principal in month 1 saves roughly $3,400 in total interest and trims about one month from the loan term — a modest but meaningful gain that compounds with regular extra payments. Always check your loan note for prepayment restrictions before structuring a strategy around this.
Total Interest Paid Over Loan Life by Down Payment Percentage ($357,400 Home, 6.42%, 27 Years)
Down Payment
Down Amount
Loan Amount
Monthly P&I (approx.)
Total Interest Paid
3%
$10,722
$346,678
$2,257
$385,750
10%
$35,740
$321,660
$2,094
$363,648
15%
$53,610
$303,790
$1,978
$341,944
20%
$71,480
$285,920
$1,862
$318,236
Moving from a 3% to 20% down payment on a $357,400 home at 6.42% over 27 years reduces total interest paid by approximately $67,500 — before factoring in PMI savings on top.
How Down Payment and LTV Ratio Affect Your Rate and Costs
Loan-to-Value (LTV) Ratio Explained
LTV = (Loan Amount ÷ Appraised Value) × 100. A $314,512 loan on a $357,400 home gives LTV = 88.0%. Lenders use this ratio as a primary risk gauge: the more equity you bring to closing, the smaller the lender's loss exposure if you default and the property must be sold.
Down Payment Thresholds That Matter
Key LTV levels on conventional conforming loans: 97% (3% down, the minimum for most conforming loans), 96.5% (FHA minimum with a 580+ credit score), 90% (typical PMI tier break), 80% (PMI disappears), and 75% (best rate tier on many loan products). Each step down in LTV typically unlocks a lower interest rate and, below 80%, eliminates PMI entirely. The general loan payment calculator can help you model different loan structures outside the mortgage context.
How LTV Influences Interest Rate Pricing
Fannie Mae's Loan-Level Price Adjustment (LLPA) grid charges borrowers additional basis points at higher LTVs. At 20% down on a $357,400 home, the loan falls to $285,920 — no PMI required, and a potentially lower rate tier. Compared to the worked example (88% LTV, $178/month PMI), a 20% down buyer saves the full $178/month PMI charge plus any rate adjustment, which over a 27-year loan totals tens of thousands of dollars. Reaching that 20% threshold requires $71,480 in cash at closing — a liquidity trade-off many buyers weigh against keeping reserves for repairs, moving costs, and an emergency fund.
FHA vs. Conventional Loan: Side-by-Side Comparison
FHA Loan Basics and MIP Requirements
FHA loans are insured by the U.S. Department of Housing and Urban Development. Per HUD Handbook 4000.1, borrowers with a credit score of 580 or above can put down as little as 3.5%. On a $357,400 home, that is $12,509 down, leaving a base loan of $344,891. HUD then adds an upfront MIP of 1.75% — $6,035 — typically rolled into the loan balance, bringing the financed amount to $350,926. The annual MIP for loans with terms greater than 15 years and LTV above 90% is 0.85%, or $2,983/year ($249/month on $350,926). Under current HUD guidelines, this annual MIP continues for the life of the loan for borrowers who put down less than 10%.
Conventional Loan PMI Rules
A conventional buyer putting down 5% ($17,870) borrows $339,530. PMI at 0.68% runs $192/month. Unlike FHA MIP, conventional PMI is cancellable: once the balance drops to 80% of the original appraised value ($285,920 in this case), you can formally request removal. Servicers must terminate PMI automatically when the balance reaches 78% LTV under the Homeowners Protection Act of 1998. A 20% down conventional loan eliminates PMI entirely from day one.
Which Loan Costs Less Over Time?
For a borrower who plans to stay in the home long-term, non-cancellable FHA MIP is the key liability. Even when the FHA rate is lower, paying $249/month in MIP indefinitely can erase that advantage within a few years. Conventional PMI, by contrast, phases out. For buyers with limited savings or credit scores below 620, FHA's more flexible guidelines may be the only path to ownership — but the long-term cost differential warrants careful modeling before committing.
FHA vs. Conventional Mortgage at a Glance ($357,400 Home, 6.42% Rate)
Feature
FHA (3.5% Down)
Conventional (5% Down)
Conventional (20% Down)
Minimum down payment
$12,509 (3.5%)
$17,870 (5%)
$71,480 (20%)
Base loan amount
$344,891
$339,530
$285,920
Upfront MIP / PMI
$6,035 (1.75%, financed)
None
None
Financed loan total
$350,926
$339,530
$285,920
Annual MIP / PMI rate
0.85% (HUD 4000.1)
~0.68%
None
Monthly MIP / PMI
$249
$192
$0
Est. monthly P&I (27 yr)
$2,285
$2,211
$1,862
MIP / PMI cancellation
Life of loan (LTV >90%)
At 80% LTV (HPA 1998)
N/A — none required
Min. credit score
580 (3.5% down)
620 (typical)
620 (typical)
Max back-end DTI
Up to 57% (case-by-case)
43–50% (DU approval)
43–50% (DU approval)
Sources: HUD Handbook 4000.1 (FHA MIP rates); Fannie Mae Selling Guide (conventional PMI and LLPA guidelines). Rates assume 6.42% fixed; actual PMI rate varies by lender and credit profile.
Monthly Payment Comparison: Rate vs. Term for $314,512 Loan
Interest Rate
27-Year Monthly P&I
30-Year Monthly P&I
Difference (27 vs. 30 yr)
Total Interest 27 yr
Total Interest 30 yr
5.50%
$1,866
$1,787
$79
$289,876
$328,808
5.75%
$1,914
$1,836
$78
$305,648
$346,448
6.00%
$1,963
$1,886
$77
$321,700
$364,448
6.25%
$2,013
$1,937
$76
$337,700
$382,808
6.42%
$2,048
$1,968
$80
$349,040
$394,968
6.50%
$2,064
$1,989
$75
$354,248
$401,528
6.75%
$2,115
$2,042
$73
$370,548
$420,608
7.00%
$2,167
$2,096
$71
$387,196
$440,048
7.25%
$2,219
$2,151
$68
$403,844
$459,848
7.50%
$2,272
$2,207
$65
$421,216
$480,008
P&I only; does not include taxes, insurance, or PMI. Bolded row matches the worked example. A 1.0% rate increase on a $314,512 loan adds roughly $200–$215/month to the 27-year payment and over $57,000 in total interest.
Common Mortgage Mistakes and Misconceptions
Mistake 1: Budgeting Only for P&I
The P&I payment is what most online calculators show by default, but the actual monthly obligation — PITI — is typically 20–35% higher. On the worked example, the P&I of $2,048 rises to $2,538 once taxes, insurance, and PMI are included. Buyers who size their budget against P&I alone often find themselves short at closing or uncomfortably stretched after moving in.
Mistake 2: Ignoring Rate Reset Risk on ARMs
Adjustable-rate mortgages carry a fixed initial period — commonly 5, 7, or 10 years — after which the rate resets annually based on an index (SOFR for most new ARMs) plus a fixed margin. A 5/1 ARM offered at 5.50% today could adjust to 8.00% or higher at year 5 depending on index movement and the loan's per-adjustment and lifetime caps. On a remaining balance above $300,000, that shift translates to $300–$600 more per month. If you plan to stay beyond the initial fixed window, a fixed rate eliminates that exposure entirely.
Mistake 3: Underestimating Closing Costs
Closing costs average 2–5% of the loan amount. On the $314,512 loan in this example, that range is $6,290–$15,726 due at closing, on top of the down payment. Costs include lender origination fees, title insurance, escrow setup, appraisal, and prepaid interest. Rolling closing costs into the loan avoids a large upfront outlay but increases the balance you pay interest on for the life of the mortgage.
Mistake 4: Confusing Pre-Qualification with Pre-Approval
Pre-qualification is based solely on self-reported income, assets, and debt figures — no documentation, no credit pull. Pre-approval requires verified pay stubs, tax returns, bank statements, and a hard credit inquiry. Sellers and their agents treat these documents very differently. Submitting a pre-qualification letter with an offer in a competitive market weakens your negotiating position considerably.
FAQ: Mortgage Calculator Questions
What is the difference between an FHA and a conventional mortgage loan?
FHA loans are government-backed and insured by HUD, allowing down payments as low as 3.5% for borrowers with credit scores of 580 or above. They carry mandatory Mortgage Insurance Premium (MIP) — 1.75% upfront plus 0.85% annually — and for most borrowers that MIP remains for the life of the loan. Conventional loans are not government-insured; they require PMI only when LTV exceeds 80%, and that PMI can be canceled once the balance reaches 80% of appraised value under the Homeowners Protection Act of 1998. Conventional loans also generally require higher credit scores (typically 620+) and have stricter DTI limits than FHA, though Fannie Mae's automated underwriting can approve borderline profiles with compensating factors.
How does PMI affect my monthly mortgage payment?
PMI is added to your monthly payment whenever you put down less than 20% on a conventional loan. Annual PMI rates typically range from 0.20% to 1.50% of the loan balance, with your exact rate determined by your credit score and LTV. On the $314,512 loan in this example at 0.68% annually, PMI adds $178/month — a real cost that continues until your balance falls below 80% of the original appraised value. Once your LTV hits 78%, your servicer is legally required to cancel PMI automatically without you having to ask. Keeping your credit score high and increasing your down payment are the two most direct ways to minimize this charge.
Can I pay off my mortgage early without a penalty?
Most conventional loans originated after January 10, 2014, are Qualified Mortgages under the Dodd-Frank Act and are prohibited from carrying prepayment penalties, so you can pay extra principal or retire the loan entirely without any fee. FHA loans also carry no prepayment penalties. Some non-QM products — private or portfolio loans that fall outside the Qualified Mortgage safe harbor — may still include prepayment clauses, typically in the first 2–5 years. Read section 5 of your Loan Note (the prepayment section) before signing, and ask your loan officer directly whether any penalty applies to your specific product.
What is a good debt-to-income ratio to get approved for a mortgage?
DTI is calculated as total monthly debt payments (including your new PITI) divided by gross monthly income. Conventional lenders generally target a back-end DTI of 43% or lower; Fannie Mae's Desktop Underwriter system can approve ratios up to 50% when compensating factors — such as significant reserves or a high credit score — are present. FHA guidelines allow back-end DTI up to approximately 57% in case-by-case approvals. A DTI below 36% is considered strong and gives you negotiating leverage; above 45% you may need to document compensating factors carefully or reduce your loan amount to qualify.
How do property taxes and homeowners insurance factor into my mortgage payment?
Most lenders require an escrow account that collects one-twelfth of your annual property tax and one-twelfth of your annual insurance premium alongside your P&I payment each month. The combined total — principal, interest, taxes, and insurance — is PITI, and it is the figure lenders use when calculating your DTI ratio. Escrow balances are reviewed annually; if your tax assessment rises or your insurance premium increases, your lender adjusts the monthly escrow contribution, which means your total payment can change even on a fixed-rate mortgage. In the worked example, taxes ($187/month) and insurance ($125/month) together add $312/month — about 15% on top of the P&I payment.
What happens to my monthly payment if interest rates rise on an ARM?
An adjustable-rate mortgage has a fixed initial period, then resets annually based on a market index (SOFR is now the standard replacement for LIBOR) plus a fixed margin set in your loan agreement. A 5/1 ARM at 5.50% could theoretically adjust to 8.00% or higher after year 5 depending on index movement — a jump that would add $300–$600 per month on a remaining balance of $300,000 or more. ARM loans typically carry two caps: a per-adjustment cap (often 2%) limiting how much the rate can move in a single year, and a lifetime cap (often 5–6% above the initial rate) limiting the total increase over the loan's life. Stress-test your budget against the lifetime cap scenario before choosing an ARM.
How much should I put down to avoid PMI?
A down payment of at least 20% of the purchase price eliminates PMI entirely on a conventional loan. On the $357,400 home in this example, that means $71,480 at closing. If you cannot reach 20%, some lenders offer lender-paid PMI (LPMI), where the PMI cost is absorbed into a slightly higher interest rate rather than charged as a separate monthly line item — useful if you plan to sell or refinance within a few years, since the rate increase is fixed rather than cancellable. FHA requires MIP regardless of down payment size, so 20% down does not eliminate that charge on an FHA loan; switching to a conventional loan is the only way to escape it entirely.
