A complete mortgage calculator with PMI, taxes, insurance, HOA, extra payments, and a biweekly schedule. Every dollar of every payment is shown to you.
Monthly payment (PITI + HOA + PMI)
$2,528
Principal & interest: $2,528
Interest saved
$0
Time shaved
0 years
New payoff date
—
Loan amount$320,000
Total interest$408,142
Total cost$728,142
Payoff date—
Where each monthly payment goes
Principal vs interest, year by year
Annual amortization. Toggle to monthly for the full month-by-month table.
Sample weekly rates from Freddie Mac PMMS — reference only. Your offer depends on credit, debt-to-income, and lender margin.
Conventional 30Y
6.78%
3% min down · 620 FICO
FHA 30Y
6.42%
3.5% min · 580 FICO
VA 30Y
6.18%
0% down · veterans
15Y conventional
5.95%
Builds equity 2× faster
When PMI drops off
Conventional loans require PMI when LTV > 80%. By federal law (Homeowners Protection Act, 1998) the lender must automatically cancel PMI when LTV reaches 78% based on the original schedule. You can request cancellation at 80% LTV.
PMI on this loan auto-cancels in: —
The math
How a fixed-rate mortgage actually works.
Every monthly payment splits in two: interest on the remaining balance, and principal that pays the loan down. Early on, almost all of it is interest — by year 30 almost all of it is principal. The shape of that crossover is what amortization is.
M = P · [ r(1+r)n ] / [ (1+r)n − 1 ]
M — monthly principal & interest payment
P — loan amount (price minus down payment)
r — monthly rate (annual ÷ 12)
n — total months (years × 12)
A useful intuition
On a 30-year mortgage at 7%, the first payment is roughly 83% interest. The crossover — when more goes to principal than interest — only arrives around year 19. That's why extra payments hurt the most.
A worked example
$320,000, thirty years, 6.5%.
Walk it by hand
1. Loan: $400,000 home − $80,000 down = $320,000
2. Monthly rate: 6.5% ÷ 12 = 0.005417
3. Months: 30 × 12 = 360
4. Apply the formula: M = 320,000 × [0.005417·(1.005417)360] / [(1.005417)360−1]
M = $2,022.62 / month (principal & interest)
Add $400/month for property tax, $125 for insurance, plus PMI until LTV reaches 78% — and the all-in PITI is closer to $2,500–2,650.
The lever that matters
Extra payments aren't a trick. They're arithmetic.
A single extra payment in year one shaves roughly three months off a 30-year loan and saves about $2,000–$5,000 in interest, depending on rate. Why? Because that $2,000 you sent in year one would otherwise have been earning interest for the lender for 29 more years.
Strategy
Months saved
Interest saved
+ $100/month
~30 months
~$33,000
+ $250/month
~62 months
~$70,000
+ $500/month
~104 months
~$116,000
Biweekly schedule
~52 months
~$58,000
Round payment up to next $100
~10–25 months
~$12–28k
Estimates: $320k loan, 6.5%, 30Y. Rerun with your numbers above.
FAQ
Questions, asked plainly.
PITI is the four-part monthly cost of owning a home with a mortgage: Principal, Interest, property Taxes, and homeowner's Insurance. Lenders qualify you on PITI relative to your gross income — generally PITI / gross income should sit below 28%.
The Homeowners Protection Act of 1998 requires the lender to automatically cancel PMI when your loan-to-value reaches 78% on the original schedule. You can request manual cancellation at 80% LTV — sometimes worth doing if home prices have risen.
Mathematically, a 15-year loan saves enormous interest (often half). Practically, a 30-year with voluntary extra payments gives you the same outcome plus the option to drop back to the lower payment in a tight year. The 15-year is cheaper. The 30-year is more flexible. Most homeowners value flexibility.
Each discount point costs 1% of the loan up front and lowers your rate by roughly 0.25%. The break-even is usually 5–8 years. If you'll refinance or sell sooner, points lose money. If you'll keep the loan, they're effectively a guaranteed return on the cash you spent.
Conventional loans typically need 620+, with the best rates appearing at 740+. FHA accepts down to 580 with 3.5% down (500–579 with 10% down). VA has no statutory minimum, but most lenders set 580–620 overlays. USDA generally wants 640+. Above the lender's threshold, every 20-point rise in FICO is worth roughly 0.10–0.20% in rate — material money over 30 years.
Conventional: 3% (first-time buyers via Fannie Mae HomeReady / Freddie Mac Home Possible) or 5% standard. FHA: 3.5% with 580+ FICO. VA: 0% for eligible veterans. USDA: 0% in eligible rural areas. The "20% down" rule is folklore — what 20% actually buys is exemption from PMI and a stronger negotiating position. For most households, putting less down and keeping reserves liquid is the better trade.
Fixed-rate locks the rate for the full term (typically 30 or 15 years). ARM (adjustable-rate mortgage) offers a lower teaser rate fixed for 5, 7, or 10 years, then adjusts annually based on an index (now SOFR, formerly LIBOR) plus a margin. ARMs cap each adjustment (often 2% periodic, 5% lifetime). They make sense if you're certain you'll move or refinance before the first reset; otherwise the rate risk usually isn't worth the small initial savings.
Extra payments shorten the term without changing the rate. Refinancing changes the rate (and usually resets the clock). If your current rate is reasonable and you have flexibility, extra payments are simpler — no closing costs, no credit pull, no reset to year one of amortization. If your rate is materially above market and you'll stay 5+ years past the break-even, a refinance plus continued extra payments beats either approach alone. The refinance calculator tells you the break-even month exactly.
The lender's ceiling (DTI ≤ 43% for QM loans) is rarely the same as the comfortable budget (PITI ≤ 28% of gross income — the "front-end ratio"). Use the home affordability calculator for the latter. Then add reserves: budget 1% of the home value per year for maintenance, plus a cash cushion of 6 months of full PITI sitting liquid before you close. The hidden cost of homeownership isn't the mortgage payment — it's the roof, the HVAC, and the property-tax assessment that arrives in year three.
On a 30-year amortizing loan at 6.5%, your first monthly payment of roughly $2,528 (on a $400k loan) splits into about $2,167 interest and $361 principal. Interest accrues on the outstanding balance, which is at its peak in month one. Each subsequent payment chips slightly more off principal. Halfway through the 30 years you've typically paid down only ~30% of the balance. This is exactly the math that makes early extra payments so valuable: a $500 principal-only payment in year 2 saves you 28 years of compounding interest on those dollars.
Glossary
Words on a mortgage paper, decoded.
LTV (Loan-to-Value)
The loan amount divided by the home's appraised value. 80% LTV is the threshold for avoiding PMI on conventional loans.
DTI (Debt-to-Income)
All monthly debt payments ÷ gross monthly income. Conventional loans usually want this under 43–45%.
Escrow
An account the lender uses to collect taxes and insurance with each payment, then pay them on your behalf.
Origination fee
The lender's fee for processing the loan — typically 0.5–1% of the loan amount.
APR vs Rate
Rate is the cost of borrowing the principal. APR also includes points, origination, and mortgage insurance — it's the truer comparison.
Sources
What we read so you don't have to.
Methodology
Standard fixed-rate amortization formula (12 CFR §1024 / §1026).
PMI auto-cancellation at 78% LTV from CFPB guidance on the Homeowners Protection Act of 1998.
Conventional/FHA/VA underwriting thresholds: HUD, VA, Fannie Mae handbooks.
This calculator is for education. Your actual rate and approval depend on credit, employment, debt, and the property. Talk to a licensed mortgage advisor before signing anything.