How to calculate Spanish VAT step by step
Adding or removing VAT from a price, with the correct formula and the most common mistake.
Tricks to calculate percentages mentally
Discounts, tips, and percentage changes, without needing a calculator.
How to make a monthly budget
Organize your income and expenses and find out how much you can really save.
How to read your payslip in Spain
Gross, net, contributions, and income tax withholding, explained plainly.
Compound vs. simple interest
The real difference, with numeric examples, a comparison table, and when each one matters.
How to start investing with little money
Concrete steps, in order, to take the first step without needing large amounts.
10 common mistakes with compound interest
The most frequent errors when calculating or interpreting it, and how to avoid them.
How much do I need to save for retirement?
How to calculate your target capital and required monthly contribution, step by step.
Compound interest examples step by step
Three worked cases with real numbers, to understand the formula applied for real.
Rule of 72
How many years it takes your money to double, without needing a calculator.
Nominal rate vs. APR
The difference that changes your calculation, explained with examples.
Taxes on compound interest in Spain
How your savings and investment gains are taxed, in general terms.
Back to the calculator
Compare scenarios or calculate how much to save each month for your goal.