About

One desk for the numbers behind every money decision.

FinanceOneDesk · financeonedesk.com

FinanceOneDesk is a growing collection of free, fast, private financial calculators. The idea is simple and a little old-fashioned: build one tool that answers one real money question, make it visual so you can feel the trade-offs, and then get out of your way. No sign-up walls, no forty-field forms, no dashboards to learn — just move a slider and watch the answer change.

Most financial websites do the opposite. They bury a simple calculation under adverts and pop-ups, gate the useful part behind an account, or quietly harvest what you type. We wanted the tools we personally reach for when a friend asks "how much do I actually need to retire?" or "is it worth overpaying my mortgage?" — tools that are honest about their assumptions and keep your numbers to themselves.

• 20 calculators, all free
• Runs entirely in your browser
• No sign-up, no account
• Your numbers never leave your device
• Open, tested methodology
• One-time Pro — no subscription

What we believe

A few principles shape every tool on the desk. They're the reason it looks and behaves differently from most finance sites.

What's on the desk

Twenty calculators, organised into eight collections, each covering a different corner of personal finance:

• Financial independence — the FIRE calculator, Coast FIRE, a retirement-drawdown model (will my money last?), compound interest, your retirement number, and the savings-rate curve that shows how the share of pay you keep sets your timeline.
• Debt & loans — a loan and mortgage calculator that reveals the true cost of interest and overpayments, and a debt-payoff planner comparing the snowball and avalanche methods across all your debts.
• Budgeting & net worth — a 50/30/20 budget planner and a private net-worth calculator that projects where steady saving takes you.
• Investing & tax — an investment projector that lays bare the lifetime cost of fees, and a generic capital-gains-tax estimator.
• Planning essentials — an emergency-fund calculator for sizing your cash cushion, and an inflation calculator that shows what your money will really be worth.
• Insurance & protection — a life-insurance calculator that sizes the cover your family would need, and an income-protection check for how exposed you'd be if illness stopped your pay.
• Property & housing — a mortgage-affordability calculator for the price your income really supports, and a fair rent-vs-buy comparison with the crossover year.
• Pensions & goals — a pension & employer-match calculator that shows the free money at stake, and a savings-goal planner that turns any target into a monthly amount.

Alongside the calculators there's a growing set of plain-English guides — longer reads for the big decisions, each linked to the free tool that does the maths.

How it works

1. 1
   Pick a question. Choose the calculator that matches what you're actually wondering — from "when can I retire?" to "how big should my emergency fund be?"
2. 2
   Move the sliders. Enter your real numbers and watch the chart and headline figure update instantly. Nothing is sent anywhere.
3. 3
   Go deeper if you want. The optional Pro unlock adds extra modelling, plain-language insights, year-by-year schedules, comparisons and CSV / printable exports across every tool.

How the calculators are built

Every tool runs entirely in your browser using transparent, well-established formulas — standard compound-interest and annuity maths, amortization schedules, and the widely used 4% "safe withdrawal" framework for retirement. Where a calculator solves for a figure (like the monthly saving needed to hit a target, or a loan's payment), we test the maths against the closed-form formula so the numbers are correct to the cent — the full formulas, assumptions and testing process are documented on our methodology page. Projections assume steady, inflation-adjusted returns unless you're told otherwise; real markets are lumpier than any model, which is exactly why we show ranges, comparisons and "what-if" levers rather than a single false-precision number.

These tools are built for education and planning, not as personalised financial advice. They deliberately leave out things that vary hugely by person and country — most taxes, product fees, means-tested benefits and the sequence of real-world returns. Treat the outputs as a clear direction of travel, then confirm any big decision with a suitably qualified professional.

Who it's for

FinanceOneDesk is for anyone who wants to understand their own money a little better — whether you're just starting to save, mapping a route to financial independence, weighing a mortgage overpayment, or sanity-checking a retirement plan. You don't need a finance background: the tools are built to make the ideas obvious. And because nothing is stored or shared, they're just as suited to a quick private "what if?" as to serious planning.

Your privacy

The numbers you type — your age, your savings, your debts — are processed on your own device and are never sent to us or stored on any server we run. We have no accounts and no database of users. Your most recent inputs and currency choice are saved only in your browser's local storage, under your control, and clearing your browser data wipes them. The one exception is advertising: like most free sites, FinanceOneDesk shows ads through Google, which may use cookies; you're asked for consent where the law requires it, and Pro removes ads entirely. The full detail is on our Privacy page.

How the site is funded

FinanceOneDesk is free, and staying free costs something to run. Two things keep the lights on: unobtrusive advertising, and an optional one-time Pro unlock (€19, no subscription) that adds deeper modelling, plain-language insights and exports across every tool — and turns off ads. That's the whole business model. We don't sell data, because we don't collect it, and there's no upsell treadmill: pay once, keep it.

Where the desk is heading

The plan is breadth without bloat: more collections, each still built around single, honest questions. On the near horizon are retirement-income drawdown planning, more long-form guides, and more long-form guides. You can see the full picture — what's live, what's in progress and what's planned — on the roadmap. The desk grows around the questions people actually ask, so if something you need isn't here yet, tell us and it moves up the list.

Common questions

Get in touch

Found a bug, spotted a number that looks off, or want a calculator that isn't here yet? The desk grows around the questions people actually ask. Email financeonedesk@outlook.com — we read everything.