Adjustable-Rate (ARM) Calculators
Model ARMs, interest-only and option loans through their fixed period and every adjustment that follows.
Adjustable-Rate Mortgage (ARM) Calculator
Project payments through the fixed period and the rate adjustments that follow on an ARM.
ARM vs. Fixed-Rate Mortgage
Compare an adjustable-rate mortgage against a fixed-rate loan across likely rate scenarios.
ARM & Interest-Only ARM vs. Fixed
Compare a standard ARM, an interest-only ARM and a fixed-rate mortgage side by side.
Interest-Only ARM Calculator
Model the interest-only period of an ARM and the payment shock when amortization begins.
Option ARM Calculator
See how minimum payments on an option ARM can cause negative amortization and a growing balance.
Fixed-Rate vs. Interest-Only Mortgage
Compare a conventional fixed-rate loan against an interest-only mortgage over time.
Fixed-Rate vs. LIBOR ARM
Compare a fixed-rate mortgage with an index-based ARM under rising and falling rate paths.
APR Calculator for ARMs
Estimate the APR of an adjustable-rate mortgage, accounting for the fixed and adjusted periods.
5/1 ARM Calculator
Five years fixed, then annual adjustments. The most common ARM, shown with the reset.
3/1 ARM Calculator
Three years fixed then annual resets. The lowest start rate, soonest reset risk.
7/1 ARM Calculator
Seven years of fixed payments before annual adjustments begin. A longer runway.
10/1 ARM Calculator
A full decade fixed before the rate starts adjusting. Closest to a fixed loan.
An ARM trades a lower starting rate for uncertainty once the fixed period ends. These calculators project payments all the way through — the initial fixed years, the first reset, and the periodic and lifetime caps that bound how high the rate can climb.
Compare a 3/1, 5/1, 7/1 or 10/1 ARM against a fixed-rate loan, model interest-only and option-ARM payment shock, and see the worst-case payment before you sign. The point is to know the risk, not just the teaser rate.
Adjustable-Rate (ARM) calculators — frequently asked
How does an ARM work?
An adjustable-rate mortgage is fixed for an intro period — five years on a 5/1, seven on a 7/1 — then adjusts periodically to an index plus a fixed margin, within caps.
You get a lower starting rate in exchange for uncertainty after the fixed period ends.
What do the numbers in a 5/1 ARM mean?
The first number is how many years the rate stays fixed; the second is how often it adjusts afterward. A 5/1 ARM is fixed for five years then adjusts once a year; a 7/1 holds its rate for seven years, then annually.
Is an ARM a good idea?
It can be if you plan to sell or refinance before the fixed period ends — you get the lower rate and leave before the risk.
If you will hold the loan long-term, a fixed rate removes the chance of a rising payment down the road.
What are ARM caps?
Caps limit how far the rate can move — an initial cap at the first reset, a periodic cap per adjustment, and a lifetime cap over the loan. Together they set your worst-case payment, which these calculators project before you sign.