FT FinToolSuite

Mortgage Planning

15 Year vs 30 Year Mortgage Stress Test

This guide explains the 15 vs 30 year tradeoff in plain language, shares a simple comparison table, and shows how to test both scenarios with the same assumptions.

Published: January 1, 2026 · Updated: January 1, 2026 · By FinToolSuite Editorial

Open the stress tester

Run a 15-year and a 30-year scenario with the same inputs and compare outputs.

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Disclaimer

  • Educational only. No guarantees. Numbers are illustrative.
  • Results depend on your inputs and assumptions.

Plain-English tradeoff

Shorter terms raise monthly payments but reduce total interest and exposure. Longer terms lower monthly DTI but extend interest and rate sensitivity. Stress tests help show how each term handles shocks.

Simple comparison table

Term Monthly payment (round) DTI mid/high Safe loan (direction)
15-year Higher Mid higher, tail higher Often lower due to stress
30-year Lower Mid lower, tail lower Often higher than 15-yr scenario

How to test both terms

Save a baseline scenario, duplicate it, change only the term, rerun, and compare the recommended safe loan, DTI mid/high percentiles, and default probability directionally.

FAQs

Should I change rate assumptions too?

Keep rate assumptions the same for a fair term comparison; test rate shocks separately.

How do I read the table?

Use it as a directional guide. Exact payments depend on your inputs.

Where do I see charts?

After running each scenario, view the DTI distribution and outputs in the tool.

Where is privacy info?

See Privacy Policy before sharing exports.

Compare terms now

Open the mortgage affordability stress tester, run 15-year and 30-year scenarios, and compare outputs side by side.

Open the stress tester