We built PennyCalc because we couldn't find calculators we trusted.

That sounds dramatic, but it's true. We're data people — the kind who build spreadsheet models for fun and run the numbers three different ways before making a financial decision. When we went to buy a house, plan for retirement, or figure out the tax implications of a Roth conversion, the existing online calculators either oversimplified the math, hid their assumptions, or were clearly just vehicles for selling you a mortgage.

We wanted tools that showed their work. Tools where you could adjust every variable and see exactly how each one affected the outcome. Tools built by people who actually agonize over whether to pay down the mortgage or invest the difference — not by a content team that's never personally navigated a jumbo loan.

So we built the calculators we wished existed.

Who this is for

PennyCalc is for people who don't just want to be told what to do — they want to see the proof in the numbers.

If you earn enough that your financial decisions have real complexity to them — jumbo loans, AMT exposure, backdoor Roth strategies, capital gains planning, rental property analysis — you've probably noticed that most financial content online is written for a different audience. It's entry-level. "What is a 401(k)?" when what you actually need is "What happens to my tax bracket if I max out my 401(k), do a mega backdoor Roth conversion, and my spouse's RSUs vest in the same year?"

That's the gap PennyCalc fills. Every calculator here handles the edge cases and advanced scenarios that the big sites gloss over, because we've personally encountered most of them.

What we actually do differently

The math is visible. Every calculator shows you exactly how it arrives at its numbers. Amortization schedules, tax bracket breakdowns, year-by-year projections — the full detail is always available, not hidden behind a "talk to an advisor" button.

The assumptions are stated. When we use an estimated property tax rate or insurance cost, we tell you what we assumed and let you override it. Nothing is a black box.

The examples are real. When we write about shopping for a jumbo loan and finding that credit union rates beat the big banks, that's because one of us literally did that. When we compare VMFXX to tax-exempt money market funds, it's because we ran that exact analysis for our own cash. The insights on this site come from experience, not research assistants summarizing Investopedia.

We don't give advice. PennyCalc is a calculator, not an advisor. We build the tools that let you run your own scenarios and reach your own conclusions. Every page includes a disclaimer because we mean it — your situation is specific, and a calculator is a starting point, not an answer.

Our background

We come from data analysis and quantitative finance. We've built demographic models across millions of data points, automated trading systems, and financial analysis tools for institutional use. We're not certified financial planners or licensed advisors — we're the people those professionals hire when they need someone to build the model.

That background is why PennyCalc's calculators work the way they do. We care about precision, edge cases, and showing the full picture. If a calculation involves a conditional (like PMI dropping off at 78% LTV, or the AMT exemption phaseout), our calculator handles it correctly instead of pretending it doesn't exist.

How PennyCalc makes money

Transparency matters to us, so here it is: PennyCalc earns revenue through display advertising and affiliate partnerships. When you see a "Compare Rates" button or a link to a financial product, clicking it may earn us a commission. This never affects the calculator results or the content — the math is the math regardless of who's advertising.

We chose this model specifically because it means the calculators are free, with no signup required, no email capture, and no paywall. You open the page, use the tool, and leave. That's it.

Get in touch

Found a bug in one of our calculators? Have a scenario our tools don't handle? We genuinely want to hear about it.

Email: [email protected]

Every calculator error report gets investigated. Getting the math right isn't a tagline — it's the entire point.