About Ground Figures
Ground Figures is a free set of mortgage and savings calculators built around one idea: you should be able to see the math, not just the answer.
Who builds this
Kulasekar Mittapalli is a software professional and the builder behind Ground Figures. He built these tools after repeatedly running into mortgage calculators that produced a number with no explanation of how they got there — and no way to check the assumptions behind it.
Every calculator on this site is written from published amortization and lending formulas, not black-box estimates. Where a figure depends on an assumption — a tax rate, an insurance estimate, a PMI percentage — that assumption is stated on the page so you can change it to match your actual situation.
Research and fact-checking contributions from Roja Mittapalli.
What this site is — and what it isn't
An educational tool
Calculators and plain-English explanations to help you understand how mortgage math actually works before you talk to a lender.
Financial advice
Ground Figures is not a lender, broker, or financial advisor, and nothing here is personalized financial, tax, or legal advice.
Nothing to sign up for
Every tool runs in your browser. We don't ask for your email, phone number, or personal financial details to show you a result.
Ads and affiliate links
The site may earn revenue from advertising and affiliate partnerships. This never changes the numbers our calculators produce.
Our editorial approach
Because mortgage decisions have real financial consequences, we hold this content to a few specific standards:
- Every number is computed, not estimated. Payment figures, interest totals, and amortization schedules come from standard published formulas. We verify our calculator outputs against the worked examples in our articles so the two always agree.
- Assumptions are stated, never hidden. If a figure assumes a 6.5% rate, a 20% down payment, or a national-average property tax rate, the page says so.
- We cite sources for factual claims. Loan limits, credit score thresholds, mortgage insurance rules, and tax rates are sourced to published references where available, and we link to them.
- We say when we don't know. Where data is approximate — like state-average property tax rates, which vary enormously by county and school district — we label it as approximate and point you to the authoritative source instead of implying false precision.
- We don't fabricate credibility signals. We don't publish invented user ratings, fake review counts, or testimonials.
Corrections
If you find an error — a wrong figure, an outdated rule, a calculation that doesn't match your own math — please tell us. We'd genuinely rather hear about it and fix it than have it sit there. Substantive corrections to published figures are made promptly, and we note the change on the affected page where the correction is material.
How the numbers are calculated
Monthly principal and interest uses the standard amortization formula:
Taxes, insurance, PMI, and HOA dues are added on top of that figure to produce a full monthly payment (commonly abbreviated PITI). Amortization schedules are generated month by month from the same formula, so the totals shown always reconcile with the payment figure above them.
Privacy
Calculators run entirely in your browser — the numbers you enter are not sent to us or stored on a server. The site uses standard web analytics to understand which pages are useful, and displays advertising which may use cookies. You're never required to provide personal information to use any tool on this site.