About Finance Calc App

Finance Calc App is a free suite of 59 financial calculators built to be fast, accurate, and completely private — every calculation runs in your browser, nothing is sent to a server.

Who's behind the site

Hi, I'm Mitch Duncan — I have a computer-science background and have spent years studying personal finance and helping friends and family work through their numbers — should I buy or rent? what's a freelance day rate actually worth take-home? when can I realistically retire? I got tired of rebuilding the same spreadsheets every time, and tired of the calculator sites that exist either being US-only, paywalled, or designed to push you toward someone's affiliate links rather than help you decide.

So I built this. The aim is straightforward: real maths, current tax tables for the four English-speaking markets I most often help people with (US, UK, Canada, Australia), every formula transparent on the methodology page, and nothing in the way of you getting an answer in under thirty seconds.

I'm not a Certified Financial Planner or a chartered accountant — and I won't pretend to be. Nothing on this site is personalised financial advice. What it is: solid, well-sourced tools for the kinds of questions a financially-curious adult can answer themselves once they have the numbers in front of them.

Why we built this

Most financial calculators online are either buried behind paywalls, cluttered with dark patterns, or give numbers without any explanation of how they were calculated. We wanted something different: straightforward tools that show their working, cite their data sources, and respect your privacy.

What makes us different

• Multi-region. Real tax brackets for the US, UK, Canada, and Australia — not just US-centric. Switch region in the top-right corner and every calculator updates.
• Private by design. Calculator inputs never leave your device. The Net Worth Tracker stores data in your browser's localStorage only. No account required for anything.
• Transparent methodology. Every tax calculator shows its tax year and links to the official source. See our full methodology & sources page. If a bracket is wrong, we want to know.
• Free forever. Ad-supported so we can keep all tools free with no feature-gating.

How we make money

Running the site has costs, and keeping every tool free means it has to pay for itself somehow. Here's exactly how, with nothing hidden:

• Display ads. The site shows ads, which cover hosting and development. They're kept away from the calculator inputs and results so they never get in the way of your answer.
• Clearly-labelled partner links. Where it's genuinely useful — comparing mortgage rates or savings accounts, say — we may include a link to a relevant service and earn a commission if you use it. Any such link carries an "advertiser disclosure" label, sits separately from the calculator, and never appears inside our guides.

The one rule we won't break: money never changes the maths. Monetization has zero influence on a calculator's result, the formulas we use, or what we recommend. We'd rather give you the honest number and lose the click than bend a tool to earn one — that's the whole reason the site exists.

Our calculators

We cover 10 categories:

• Mortgages & Home — Buy, refinance, and sell — payments, affordability, and the costs in between.
• Loans & Debt — Pay off loans and debt faster — and for less interest.
• Income & Paycheck — Turn a salary into real take-home pay.
• Tax — Estimate what you owe — income, capital gains, crypto, and sales tax.
• Savings — Grow your savings toward a goal with the power of compounding.
• Investing — Returns, dividends, and what inflation does to your money.
• Retirement — Project your nest egg and the income it can support.
• Family & Life — Plan for the big life events — what they cost and how to save for them.
• Bitcoin & Crypto — Historical returns, DCA simulation, unit conversion, and crypto taxes — data, not predictions.
• Everyday — Quick money tools for day-to-day life.

Editorial standards

Every calculator on this site is built around a published formula and (for tax-bearing tools) the current official tax tables, with sources cited on the methodology page. Tax brackets are refreshed within two weeks of each market's official publication. Calculator outputs are estimates — see limitations below.

Accuracy and limitations

We update tax tables annually and cite the official source for each jurisdiction. That said, tax law is complex — our calculators use standard deductions and simplified models that may not reflect your exact situation. Always verify figures with a qualified professional before making financial decisions. See our disclaimer and terms of service for full details.

Feedback and corrections

Found a bracket that's out of date? A calculator that gives wrong results? Please get in touch — accuracy matters and errors get fixed quickly.