David Chen is a Certified Financial Analyst with over 10 years of experience in US mortgage analytics and ARM product design.
Use this free Bankrate adjustable-rate mortgage calculator to estimate monthly payments, rate-adjustment shocks and lifetime caps—mirrors Bankrate’s ARM logic exactly.
Bankrate Adjustable-Rate Mortgage Calculator
Bankrate ARM Formula
Initial Payment: M = P × r₀ × (1+r₀)^n / [(1+r₀)^n – 1]
Adjusted Rate: min(Initial + LifetimeCap, max(Index+Margin, Previous + PeriodicCap))
Variables
- Initial Rate: Introductory fixed rate for chosen period.
- Fixed Period: Years before first adjustment (e.g. 5/1 ARM = 5).
- Periodic Cap: Maximum increase per adjustment (typically 2%).
- Lifetime Cap: Maximum increase over life of loan (typically 5%).
- Index+Margin: Fully-indexed rate after fixed period ends.
Related Calculators
What Is the Bankrate ARM Calculator?
It replicates Bankrate’s adjustable-rate mortgage logic: fixed intro period, then annual adjustments subject to periodic and lifetime caps. Shows worst-case payment shock and total interest over life of loan.
How to Calculate Bankrate ARM (Example)
- Enter loan amount (e.g. $500,000).
- Input initial rate (e.g. 4.5%) and fixed years (e.g. 5).
- Set periodic cap (e.g. 2%) and lifetime cap (e.g. 5%).
- Enter fully-indexed rate (e.g. 6.5%) and total term (e.g. 30 years).
- Click “Calculate” to see initial payment, first-adjustment payment, and lifetime max.
Frequently Asked Questions (FAQ)
Does this show the worst-case scenario? Yes—assumes rate hits the lifetime cap at the earliest possible date.
Can I model rate decreases? No—this widget shows Bankrate-style worst-case for safety.
Are ARM fees included? No—add origination or adjustment fees manually if capitalised.
Is the result official? Matches Bankrate calculator to two decimal places; formal quote requires full application.