Last updated: August 30, 2026
What this is
Salary to Life answers two questions almost nobody is sure about and no payslip explains: how much of your gross salary actually reaches your account, and what the part you manage to save turns into over time.
The first is answered by the take-home pay calculator, which separates social contributions, income tax withholding and what is left, then splits that remainder between your spending and your saving in a flow diagram. The second is answered by the compound interest calculator, which projects a regular contribution across the years and shows how much of the result you put in and how much the interest did.
They are built for the moment before you decide something: taking an offer, moving country, raising the monthly contribution. Not for filing a tax return.
How it works
The calculations run entirely inside your browser. There is no server receiving your figures, no account to create, nothing to confirm by email: you open the page and it is already working. The practical consequence is that your salary goes nowhere; the technical one is that the tool answers instantly as you drag a control.
What you type is kept in your own browser so it is still there when you come back, and it disappears the moment you clear the site's data.
The eight countries
Spain, France, Ireland, Luxembourg, the Netherlands, Portugal, Switzerland and the United Arab Emirates. The selection is not arbitrary: they are common destinations for anyone considering work abroad from Spain, and between them they cover very different tax models.
Several also vary internally. Spain's fifteen regional scales are modelled; in Switzerland each canton carries its own rates and multipliers, which move independently. The Emirates levy no income tax at all, and that is reflected exactly as it is.
Where the numbers come from
Each country is implemented from the tables its own tax authority publishes: the bands, the rates, the contribution bases, their ceilings, and the reliefs and credits that apply generally.
None of them is taken on trust once written. Every implementation is checked against that country's official calculator at several income levels, and the result has to match to the cent or be explained. Where a figure depends on a parameter revised annually — a reference index, a minimum wage, a contribution ceiling — that parameter is written out separately with its source beside it, so that next year's update is changing a number rather than reinterpreting the law.
On top of that sit automated checks that run on every change: that the breakdown adds back up to the gross, that earning more never leaves you with less net, and that the effective rate never exceeds the marginal one. These hold in any well-modelled tax system, so a new country inherits them on the day it arrives.
The code is published on GitHub, with the official source for each parameter annotated in that country's own file.
What it does not do
This deserves the same clarity as the rest. It is a general model, and a general model cannot capture:
- Personal and family allowances that turn on your particular circumstances.
- Income other than employment income, or special expatriate and inpatriate regimes.
- Double taxation treaties, if you are taxed in more than one country.
- The annual return's adjustments against what was withheld month by month.
That is why the results are estimates rather than advice. For a decision that matters, a professional who can see your whole situation will be right where this can only approximate.
Who is behind it
It is a personal project, not a company and not an accountancy firm's product. It came out of a need of its own: comparing job offers in different countries and finding no tool that did the whole sum without asking for an email address first.
The terms of use and the limits of what is calculated here are set out in the legal notice.
How it is funded
By advertising. The tools are free, there is no paid tier, no registration wall and no data sold to anyone; the ads are what pays for hosting and for the time spent keeping it current.
What advertising does not do is touch the results. No advertiser influences how a tax is computed or which country comes out ahead — not least because the calculation happens in your browser and anyone can read the code that does it.
Getting in touch
If you find a calculation error, a country modelled wrongly or a figure that is no longer current, that is the single most useful message you can send. The address is salarytolife@gmail.com, and the contact page has the detail.