Why I Built This Calculator

I’m Shahid Sadiq, a software developer and freelancer on Upwork from Chiniot, Punjab, Pakistan.

In 2016, a close friend migrated from Pakistan to Australia. By 2024, they’d saved enough to buy their first home using a mix of savings and a mortgage loan. When they asked me, “Should we pay extra to kill this loan fast, or invest the cash?” I started researching.

I checked 6 online calculators. Each gave different payoff dates for the same inputs. Most hid the amortization schedule. All pushed refinance ads or “offset account” upsells. As a developer, I knew the math wasn’t that complicated — the problem was transparency.

So I spent 200+ hours reading primary sources and built the calculator I wished existed: one that shows the exact month-by-month math banks use in both U.S. and international loans, cites government sources, and never changes results for sponsors.

My Research Methodology

This calculator and all content on this site are built on primary sources, not finance blogs. Every formula and strategy is verified against:

• CFPB Loan Estimate Explainer — For U.S. payment breakdowns and prepayment rules
• HUD Handbook 4000.1 — For FHA loan amortization and escrow guidelines
• Federal Reserve Bank of St. Louis FRED — For historical rate data and amortization research papers
• IRS Publication 936 — For mortgage interest deduction rules used in U.S. tax comparisons
• ASIC MoneySmart & RBA — For Australian offset accounts and variable rate structures
• NMLS Consumer Access — For state-by-state prepayment penalty laws

I also manually audited 300+ consumer complaints in the CFPB Complaint Database about “extra payment applied incorrectly” to understand how servicers mishandle principal payments. That’s why this site emphasizes “write Principal Only” on every strategy page — it’s the #1 trap globally.

Credentials & Experience

• Technical: 5+ years building financial calculation tools in JavaScript and Python. All amortization formulas on this site are open-source verifiable.
• Research: 200+ hours studying U.S. and Australian mortgage regulations. Cross-referenced every calculator result against Bankrate, ASIC MoneySmart, and RBA calculators to identify discrepancies.
• Geographic Expertise: Based in Pakistan with close ties to migrants in Australia. I understand currency risk, inflation differences, and why payoff decisions matter for overseas homeowners managing loans in AUD vs USD.
• Regulatory Review: Completed CFPB’s “Know Before You Owe” mortgage training modules and ASIC’s RG 209 credit licensing guidance to understand disclosure requirements in both countries.

Editorial Standards & Trust Signals

1. No Financial Incentives

I don’t sell mortgages, earn refinance commissions, or accept payment to change calculator results. This site is monetized via display ads only — ad networks cannot influence math outputs.

2. Cite Primary Sources

Every strategy page links to .gov or central bank sources in footnotes.

Example: Our amortization guide cites Federal Reserve Bulletin 2023-Q4 and RBA Mortgage Pricing 2024. We never use “expert blogs” as sources for YMYL claims.

3. Corrections Policy

Found an error in our math or an outdated rate? Email me at shahidsadiqtmp@gmail.com. I personally review every technical question and publish corrections within 48 hours with a changelog.

4. Update Schedule

Rate examples and tax figures are reviewed quarterly. U.S. and Australian statute references checked annually. All guides show “Last updated” dates at the top.