We built PennyCalc because the existing calculators didn't work for people like us.
Three Yale classmates working across industries and locations, but faced the same challenges. We all built financial models in Excel and Google Sheets for ourselves — mortgage comparison spreadsheets, hotel/airline point optimization, 401(k) projections, RSU tax estimators — and passing them around in our group chat whenever someone had a big financial decision coming up.
Josh was modeling leveraged buyouts at a major PE firm, but couldn't find an online calculator that handled PMI cancellation at 78% LTV correctly (he was buying his first home in Manhattan). Jessie had just left an MBB consulting role for a marketing role at a large CPG brand, and was building her own Roth conversion analysis in Google Sheets because every online tool assumed she was a median earner. Michael was leading technology go-to-market at an enterprise software company and had rebuilt the same 401(k) optimizer in Excel four times because colleagues kept asking for a copy.
At some point, we looked at the collection of spreadsheets we had developed and realized: these are better than what's widely available. Not because we're smarter, but because we actually use them, test them, and refine them. We built for our own edge cases and it turns out those edge cases are pretty common among people who earn well and have complicated financial lives.
So we turned the chat-shared spreadsheets into a website.
Who this is for
PennyCalc is built for people whose financial lives have real complexity. Jumbo loans. AMT exposure. Backdoor Roth strategies layered on top of RSU vesting schedules. Capital gains planning across multiple holding periods. SALT cap scenarios.
Most financial content online is written for someone asking "what is a 401(k)?" That's fine, but it's not you (nor is it us). You know what a 401(k) is, but you want to know how to maximize your returns. What happens to your tax bracket if you max it out, do a mega backdoor Roth, and your spouse's RSUs vest in the same year. Our calculators handle that because we've personally dealt with every one of those scenarios.
What we actually do differently
The math is visible. Every calculator shows you how it gets its numbers. Amortization schedules, bracket breakdowns, year-by-year projections. No "talk to an advisor" wall. No black boxes.
The assumptions are stated and overridable. When we default to a 1.1% property tax rate or $1,200/year homeowner's insurance, we tell you and let you change it. Your county's rate is probably different and you should use yours.
The examples come from real decisions. When we write about shopping for a jumbo loan and finding that credit union rates beat the big banks, that happened. When we compare PMI elimination strategies at 78% vs. 80% LTV, that's an analysis one of us ran for an actual purchase. The insights on this site come from decisions we made with our own money.
We don't give advice (and that's not our job). We build tools that we use ourselves and share them with you. Run your scenarios, draw your own conclusions, and talk to a professional if you need guidance specific to your situation.
The team
Josh
The Numbers Person
Started in investment banking, now works at one of the largest alternative asset managers in private equity. Josh builds the financial models behind every calculator on this site. He's the reason our tools handle conditional logic that other sites skip (PMI phaseouts, AMT exemption cliffs, bracket stacking when you have salary plus RSU income plus capital gains in the same year). If there's a rounding error three decimal places deep, he'll find it before we publish.
Jessie
The Content Person
Spent several years at MBB advising Fortune 500 clients before moving to marketing leadership at a major consumer brand. Jessie writes the supporting content, runs the SEO strategy, and is the voice check for everything we publish. Her rule: if it reads like it could appear on any generic financial site, it gets rewritten until it sounds like something we'd actually say to each other. (Her pet peeve is AI 'buzzword BS.')
Michael
The Builder
Former consultant at a leading global firm where he advised enterprise technology companies on go-to-market strategy. Now leads GTM at a high-growth data and AI company. Michael built the site, handles performance, and makes the design decisions. He's the reason PennyCalc loads fast, works on your phone, and doesn't ask for your email before showing you a number. Although truth be told, he's tinkering with everything to understand how it works in order to make it better.
How PennyCalc makes money
We're transparent about this: PennyCalc earns revenue through display ads 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 calculators or the content. The math doesn't change based on who's advertising. We chose this model because it means the tools are free — no signup, no email capture, no paywall.
Get in touch
Found a bug in a calculator? Have a scenario our tools don't cover? We want to hear about it.
Email: [email protected]
Every error report gets investigated. Getting the math right is the whole point.