Trigger rate
See when a variable-rate mortgage payment hits the trigger point and how much buffer remains.
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Trigger rate
Calculate the trigger rate, payment shortfall, and required increases to maintain amortization.
How this calculator works
Estimate the rate where your payment no longer covers principal on a variable mortgage.
Use it to plan for rising rates and avoid negative amortization surprises.
Inputs you will need
- Current mortgage balance
- Variable rate and payment amount
- Amortization length
Assumptions and limitations
- Assumes payments stay fixed while rates change.
- Lender policies may require payment adjustments.
- Use conservative scenarios for planning.
Example scenarios
Payment stays fixed
See the trigger rate where principal stops decreasing.
Payment increase scenario
Test a higher payment to avoid trigger risk.
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Create a free account to save scenarios, compare options side by side, and share results with your broker team.
Frequently asked questions
What is the trigger point?
It is when the balance stops decreasing and amortization begins extending.
Do all lenders use the same trigger rules?
No. Lender policies vary on when payments are adjusted.
Is this only for variable mortgages?
Yes. Fixed mortgages do not have trigger rates.