CalcWise
Find a calculator Browse all

ABOUT CALCWISE

I'm one person building tax and finance calculators that show their work.

Self-employed people and small business owners need to run numbers and know how the answer was built, not just get a number back. CalcWise covers the full range of small-business finance, from business taxes and depreciation to bookkeeping and margins, payroll and owner pay, cash flow and planning, entity setup, retirement, and loans and financing, with every calculator showing its formula, assumptions, and sources on the page. I'm Aaron Jegla, the one person building all of it.

WHO I AM

Who I am

Aaron Jegla, founder of CalcWise

I'm Aaron Jegla, the founder of CalcWise. I design and build the site's financial calculators and write the educational guides that go with them. I research the formulas, test them across edge cases, and document the assumptions and sources behind each tool so the math is transparent rather than a black box.

Here's what I've actually done and what I'm working on, with links you can verify:

Education

  • 2021 to present (expected 2027)

    B.S. in Finance, Personal Financial Planning concentration, Southern New Hampshire University. In progress.

Credentials (verified on Credly)

Professional development (course completions, not certifications)

  • Apr 2023

    Applied Marketing Strategies (Soomo Learning)

  • Nov 2024

    Accounting Foundations (LinkedIn Learning)

  • Nov 2024

    Bookkeeping Foundations (LinkedIn Learning)

  • Nov 2024

    Cash Flow and Business Profitability (LinkedIn Learning)

  • Dec 2024

    Taxes for Small Business (LinkedIn Learning)

Beyond the courses and credentials, I've spent the last several years managing my own personal and business finances, doing all the bookkeeping for my own business, and helping family and friends work through budgeting, investing decisions, mortgages, home equity lines of credit (HELOCs), and consumer loans.

I'm also pursuing eligibility for CFP certification. To be clear, I have not earned it, and nothing on this site should read as if I have. It is a goal, not a credential.

SOLO, HONESTLY

What "solo" actually means here

Let's get the obvious weakness out of the way first. I do the research, the math, the code, the writing, and the review. There is no team of specialists behind this and no review board. When a calculator here is wrong, there is exactly one person responsible, and it is me. Yes, I know that is both the strength and the weakness of the whole site, and I am not going to pretend otherwise.

It is also the feature. Nothing gets handed off or diluted on the way to the page. The person who read IRS Publication 946 is the person who wrote the formula is the person who coded it is the person who wrote the explanation you are reading. If something does not add up, there is no chain of people to chase. You email one person, and that person can actually answer because they built it.

WHY THIS EXISTS

Why I built this

What annoyed me about the tax and finance calculators already out there is that the big companies behind them don't explain how the calculations work on the backend. You put your numbers in, you get a number back, and that's it. Whether it's actually right doesn't seem to be the point. The point is to give you a number and then push whatever software they're selling on top of it, tax software, finance software, the thing they actually make money from. The useful information isn't what they're selling. They're selling the software, and the calculator is just the hook.

When I was doing my own bookkeeping, I kept hitting the same wall. I needed to know how a calculation worked, not just what the answer was, and the calculators I found wouldn't show me. The guides were either too thin to be useful or wrapped around a pitch. So I started building it myself, so that I know how each function works and so that you can know too.

Even if a CalcWise calculator is still running last year's tax numbers, you can see the method, see where each figure comes from, and adjust it for this year yourself. A current black-box calculator is less useful to me than a stale one that shows its work. I would rather know how an answer was built than trust a number I cannot check.

"A current black-box calculator is less useful to me than a stale one that shows its work."

WHAT I'M NOT

What I'm not

THE METHOD

How every calculator is built

Every calculator here follows the same four steps.

  1. Start from the source. IRS publications, the tax code, and federal agencies come first, before any formula gets written.

  2. Check the math. I work the formula by hand and against worked examples in the source before it goes anywhere near code.

  3. Show the work. The formula, the assumptions, the sources, all of it goes on the page next to the result, where you can see it.

  4. Keep it current. When a rule or a figure changes, I re-verify it and stamp what has been reviewed and when.

Every calculator also surfaces its own limitations as warnings on the page, not as assumptions hidden in the code. If a calculator does not model your situation, it tells you, rather than handing you a number that does not apply.

Sources come in a strict order.

  • IRS primary sources first (publications, forms, the code, Revenue Procedures).
  • Then other federal agencies (DOL, SBA, SSA, CMS).
  • Then authoritative industry and academic sources.
  • Reputable secondary sources are used only to locate the primary source, never as the final citation.

If you spot a wrong number, tell me, and I will fix it and note what changed. For more detail on each step, see the full methodology page.

HOW THIS IS FUNDED

How CalcWise is funded

CalcWise does not make money right now. No ads, no subscriptions, no affiliate links, nothing. That will change eventually. The plan is to run non-intrusive ads that create as little friction as possible for the person using the tool.

What will not change is this: the calculators are not a sales machine. I will not use them to push software, services, or products on you. The calculator exists to give you a real answer you can check, not to funnel you toward a purchase. Ads, if and when they show up, will not influence the formulas, the results, or what gets built next. If that ever changes, I will say so on this page first.

THE COLOPHON

How this site is built

CalcWise is a static site built on Astro 5. No client framework, no hydration, no React. Each calculator page ships one module script for the math and nothing else; the rest of the site carries no JavaScript beyond a small hover-prefetch helper. Every calculation runs in your browser, and your inputs never leave your device. There are no accounts and no sign-up wall.

House rules

  • No black-box calculators. Every tool shows its formula and its sources on the page.
  • No sign-up wall, ever.
  • Analytics via Plausible: cookie-free, privacy-friendly, aggregate page views only.
  • No animated number count-ups, and no motion that ignores reduced-motion preferences.
  • No invented ratings, reviews, or testimonials, because there are none.
  • No blue-and-purple fintech palette, no glassmorphism, no decorative gradients.

Last reviewed July 7, 2026.

GET IN TOUCH

Get in touch

Email is the best way to reach me: aaron@calcwise.org. I read everything that comes in. I cannot promise a fast reply, but I do read it.

If you spot a wrong number anywhere on the site, tell me. That is the most useful email I can get.

For the full contact page — including how to report a wrong number, request a calculator, or see what I can’t help with — see the Contact page.