The final Social Security bill for Autónomos in Spain depends on their exact earnings as determined in the yearly tax return.
During the year, they are expected to estimate how much they will probably earn, and set their contribution accordingly.
Seguridad Social then does the final reckoning for the year, called regularización.
This can take another year: the regularización for 2024 was mailed to people in spring of 2026.
This calculator allows you to see where you stand, whether you can expect a bill or a refund for a given year, or to adjust the current year's payments so you don't have to worry about a huge bill in the future.
This calculator works best for years in which you have received no discounts, and been registered for the whole year.
For years in which you were on the tarifa plana, off sick for longer than 2 months, have taken extended breaks, or enjoyed some of the other discounts, take results with a grain of salt: treat them as an estimate rather than a guaranteed number.