This calculator turns a headline return into the figures that are easier to compare: net return after a simple tax assumption and annualized return over the holding period.
ROI Calculator
Compare initial investment, exit value, fees and taxes to see net return before deciding.
SIMULATOR
Your numbers
Recalculates instantly as you move the sliders.
ESTIMATED RESULT22.7%
NET GAIN€4,617
ESTIMATED TAX€1,083
ANNUALIZED RETURN1%
Capital invested€20,300
Gross final value€26,000
Net final value€24,917
Compare the cost basis, final value and what remains after the progressive tax estimate.
Tax assumption: applies 19%, 21%, 23%, 27% and 30% progressively to positive gains as if there were no other savings income. Your actual tax may differ.
Save my ROI of 22.7%. Estimated net ROI with declared costs and progressive Spanish tax on positive gains; it excludes other savings income and loss offsets.
Enter the invested amount, final value, total buy and sell costs and holding period. The tool calculates gross gain, estimates progressive Spanish savings tax, shows the net result and annualizes it.
Cost basis is the initial investment plus declared costs. Gain is final value minus cost basis. Estimated tax applies the combined Spanish savings brackets in force since 2025 progressively (19%, 21%, 23%, 27% and 30%), assuming no other savings income. Net ROI divides after-tax gain by cost basis; annualized return converts that result to the selected period.
If $10,000 grows to $15,000 in 5 years, the gross return is 50%, or about 8.4% annualized. A 19% tax on the $5,000 gain leaves $4,050 net, or 40.5% net ROI.
Two investments with the same total ROI can be very different once timing, taxes and fees are considered. Annualization helps compare results over different time horizons.
Avoid comparing a five-year gain with a one-year gain using only total percentage. Also avoid treating gross return as the amount that actually ends up in your pocket.
Assumptions: estimate for a Spanish tax resident with no other savings income, offsettable losses or personal adjustments. It includes declared costs and applies the 19%, 21%, 23%, 27% and 30% brackets; it is not a tax filing calculation.
Spanish Tax Agency (AEAT) — Savings tax base · CNMV — Investor Education
ROI Calculator, with context
Does ROI account for time?
Basic ROI does not. That is why the calculator also annualizes the result.
What tax rate is used?
A simplified 19% rate on positive gains. Real taxation depends on amount, country and personal situation.
Can losses offset gains?
In many cases they can within legal limits, but the calculator does not model every tax rule.
Are fees included?
Include them in the invested amount or final value if you want a more realistic estimate.
Illustrative results for educational purposes · Educational information, not financial advice.