Question 1

How is my monthly mortgage payment calculated?

Accepted Answer

Monthly P&I uses the standard PMT formula: P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount, r is the monthly rate, and n is the total months. We add monthly property tax, homeowners insurance, HOA, and PMI to produce the full PITI.

Question 2

When does PMI drop off?

Accepted Answer

Federal law (the Homeowners Protection Act of 1998) automatically removes PMI when your loan-to-value ratio reaches 78% of the original home value on the amortization schedule. This calculator detects that month and shows you exactly when PMI ends and how much you'll have paid in PMI total.

Question 3

Are biweekly payments really better?

Accepted Answer

Yes — paying half your monthly payment every 14 days produces 26 half-payments per year, equivalent to 13 monthly payments. On a typical 30-year mortgage that shortens the loan by ~4-5 years and saves tens of thousands in interest. Toggle the Payment Frequency selector to see the impact.

Question 4

How much house can I afford?

Accepted Answer

Use the Affordability tab. Enter your gross monthly income, total monthly debts, down payment, and a target DTI ratio (28% conservative, 36% standard, 43% maximum). The tool derives your maximum home price by inverting the PMT formula and accounting for taxes, insurance, and HOA scaling with home value.

Question 5

Should I refinance?

Accepted Answer

Use the Refinance tab. Enter your current balance, rate, payment, and remaining months alongside the new rate, term, and closing costs. The tool computes monthly savings and break-even months — the threshold at which the closing costs are recouped. If you'll stay in the home longer than the break-even, refinancing saves you money.

Question 6

Are mortgage points worth it?

Accepted Answer

Use the Points tab. Each point costs 1% of the loan amount upfront and typically reduces your rate by 0.25%. Points pay off only if you keep the loan past the break-even month. If you might refinance or sell sooner, skip the points.

Question 7

Is my financial data sent to a server?

Accepted Answer

No. All calculations run entirely in your browser using JavaScript. Nothing you enter is uploaded, logged, or stored on a server. Saved scenarios live in your browser's localStorage only.

Month	Payment	Principal	Interest	PMI	Balance	LTV
Month	Payment	Principal	Interest	PMI	Balance	LTV
1	$1,886.46	$253.12	$1,516.67	$116.67	$279,746.88	79.9%
2	$1,886.46	$254.49	$1,515.30	$116.67	$279,492.38	79.9%
3	$1,886.46	$255.87	$1,513.92	$116.67	$279,236.51	79.8%
4	$1,886.46	$257.26	$1,512.53	$116.67	$278,979.25	79.7%
5	$1,886.46	$258.65	$1,511.14	$116.67	$278,720.60	79.6%
6	$1,886.46	$260.05	$1,509.74	$116.67	$278,460.54	79.6%
7	$1,886.46	$261.46	$1,508.33	$116.67	$278,199.08	79.5%
8	$1,886.46	$262.88	$1,506.91	$116.67	$277,936.20	79.4%
9	$1,886.46	$264.30	$1,505.49	$116.67	$277,671.90	79.3%
10	$1,886.46	$265.73	$1,504.06	$116.67	$277,406.16	79.3%
11	$1,886.46	$267.17	$1,502.62	$116.67	$277,138.99	79.2%
12	$1,886.46	$268.62	$1,501.17	$116.67	$276,870.37	79.1%

Mortgage Calculator

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