ARM Mortgage Payment Calculator
Payment before and after an adjustable-rate reset.
Enter your values
ⓘ Live results
Results
- Initial fixed payment
- $2,271.16
- Balance at reset
- $369,842.41
- Rate after cap applied
- 7.5%
- New payment estimate
- $2,733.10
- Payment increase
- $461.95
Quick answer
An ARM's payment stays fixed during the initial period, then adjusts (usually up) based on the index rate plus margin, subject to periodic and lifetime caps.
New rate = index + margin, capped by adjustment limits
How to use the ARM Mortgage Payment Calculator
- 1Enter the loan amount, initial rate and fixed period length.
- 2Estimate the rate you might see after reset (based on current index + margin).
- 3The calculator applies your periodic cap so the increase isn't unrealistic.
Worked example
Using the values the calculator loads with:
Inputs
- Loan amount400000 $
- Initial rate5.5 % APR
- Fixed period5 years
- Total term30 years
- Estimated rate after reset7.5 % APR
- Periodic adjustment cap2 %
Results
- Initial fixed payment$2,271.16
- Balance at reset$369,842.41
- Rate after cap applied7.5%
- New payment estimate$2,733.10
- Payment increase$461.95
Frequently asked questions
What limits how much my rate can rise?
ARMs have periodic caps (per adjustment) and lifetime caps (total increase over the loan) spelled out in your note.
Should I get an ARM?
It can save money if rates stay low or you'll sell/refinance before the reset, but carries risk if rates rise.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.