Mortgage Calculators

Option ARM Calculator

An option (pick-a-payment) ARM lets you choose among several payment levels — but the minimum payment can cause your balance to grow. See all the options.

Inputs

Loan amount

Note interest rate

Minimum-payment rate

Loan term (years)

Estimates only. Change any value to recalculate instantly.

Minimum payment $1,580.48 adds $586.18/mo to your balance

Minimum payment $1,580.48

Interest-only $2,166.67

30-year payment $2,528.27

15-year payment $3,484.43

Minimum payment vs interest owed

Minimum payment $1.6k
Negative amortization $586

Loan balance Balance (minimum payments)Original loan

Warning: the minimum payment is $586.18 less than the interest owed, so your balance grows each month — negative amortization. Option ARMs are risky; the minimum payment is rarely the smart choice.

Balance if you pay only the minimum (to a 5-year recast)View table

Year	Min payments	Interest charged	Year-end balance
1	$18,966	$26,213	$407,248
2	$18,966	$26,699	$414,981
3	$18,966	$27,217	$423,231
4	$18,966	$27,769	$432,035
5	$18,966	$28,359	$441,428

How this calculator works

This calculator runs entirely in your browser — nothing you enter is sent anywhere, and there is no sign-up. Change any input and the result, breakdown, and schedule update instantly.

Rate and cost fields are pre-filled with current benchmarks (Federal Reserve / Freddie Mac via FRED (St. Louis Fed)), so your first result is already realistic — replace them with your own quote to see your numbers. To weigh one option against another, use the loan comparison calculator.

30-year fixed mortgage rate, 2019–2026

Source: Freddie Mac PMMS via FRED. Annual averages; latest weekly reading shown.

Common questions

Is this calculator free, and do I need to sign up?

Yes and no — it is completely free and asks for no account or personal details. Every calculation happens in your browser, so nothing you type is stored or sent to us.

How accurate are the results?

The math is exact for the inputs you give it, but the defaults are national benchmarks — your real rate, fees, taxes, and insurance will differ. Treat the result as a close estimate to refine with a real quote.