An editorial library of forty-five financial calculators. No ads, no sign-up, no data leaving your browser. Just the math behind the choices that matter.
Three calculators we keep returning to — for the homebuyers, the long-term investors, and anyone who wants to know when work becomes optional.
Type a price, a rate, and a term. Watch how much of every payment is interest, and how that ratio shifts over thirty years.
Open the tool № 02 — InvestWhy decades matter more than dollars, and what a single percentage point of return looks like over a lifetime.
Open the tool № 03 — PlanThe four-percent rule, your savings rate, and the year you'd reach financial independence — laid out in one number.
Open the toolForty-five calculators, organised by intent. Each one comes with the formula, a worked example, and the assumptions written down so you can argue with us.
— A note from the editor
We built TopFinClub because the calculators we found online wanted our email, sold us mortgages, or buried the formula behind a paywall.
This site is the opposite. The math runs on your machine. We won't ask who you are. We will, however, show our work.
Every calculator publishes the equation it uses, the assumptions it makes, and a worked example you can verify by hand.
Inputs never travel. Saved scenarios live in your browser's local storage. Close the tab and the trail closes with it.
No advisor referrals, no affiliate mortgage rates, no "speak to a partner". Just the calculator and the citations.
The math is universal. The interface ships in English, Español, Français, Deutsch, Português, 中文, 日本語, العربية, हिन्दी, Italiano, and 한국어.
All forty-five calculators are free. There is no registration, no subscription, and no hidden cost. The math runs locally in your browser — no number you type ever leaves your device.
Forty-five calculators across six categories: borrow & own (mortgage, refinance, HELOC, rent-vs-buy, home affordability, amortization, loan, auto loan, credit card, debt-to-income), invest (compound interest, simple interest, ROI, stock return, dividend, DCA, CD), save (savings goal, emergency fund, college savings, budget), plan (retirement, 401(k), Roth IRA, FIRE, net worth, inflation, tax bracket, paycheck, salary US, salary UK), and business (break-even, currency).
They stay on your device. The calculators are static HTML and JavaScript — there is no backend listening for inputs. If you save a scenario, it goes to your browser's local storage. Clear your cookies and it's gone.
The math is standard — amortization, future value, CAGR, PITI — and is sourced from CFPB, IRS, and BLS publications. We test against Bankrate, NerdWallet, and Investor.gov for the same inputs. That said: these are educational tools, not advice. For decisions with consequences, talk to a licensed advisor.
Each tool can print to PDF with the formula and assumptions appended, save up to ten scenarios in your browser, and share a URL that recreates the inputs when opened.
— Begin where it matters most
Whatever the question — should I refinance, can I retire at fifty-five, is my emergency fund enough — there's a calculator for it. Find yours.
Browse the library