Is it time to raise your income?

This calculator compares what you earned in a past year with what you earn today and helps you decide whether it is time to raise your income: it tells you whether your pay has kept ahead of inflation or fallen behind it, in the UK or Spain. It works with an annual salary, a day rate or an hourly rate, so it suits employees as well as freelancers and contractors.

It gives you four figures: the buying power you have gained or lost, what you would need to earn today to stand still, the gap between that and what you earn, and the money you have missed out on along the way. If you are losing ground, it suggests what to do with that number: the pay rise you would need to ask for or the rate you should be charging, and how much you would need to bring in elsewhere each year if you cannot raise it. If you fill in what you earned each year, the result is exact; if you only enter the first and last year, it spreads the pay rises evenly and tells you so.

The data is official: the annual average CPI from the ONS for the UK and from the INE (Spain's national statistics office) for Spain, from 1990 onwards. It is updated every January, once the December figure is out. The current year is left out because it does not have an annual average yet.

What it doesn't do

• It works with gross figures, before tax.
• It does not compare your income with other people's or between countries.
• It cannot tell whether you changed job or hours: it assumes both figures are comparable.
• It stores nothing: the calculation runs in your browser.