Tools for investors
Free calculators that run in your own browser. There is no account and the numbers you enter are never sent to us. By default nothing is stored; only if you choose “Save this plan on this device” in the ETF calculator is a plan kept in your own browser, and you can delete it there at any time. The results are worked examples, not advice.
ETF Calculator See what ongoing fund costs (TER) take from an ETF over the years, with a chart, several funds and a list of brokers.
Compounding calculator See how a starting amount and a fixed monthly amount grow at a return you choose.
Compare ETF costs Put the TER of two ETFs side by side and see what the difference adds up to over the years.
Purchasing power calculator See how much purchasing power an amount loses over the years at an inflation rate you choose.
Market crash simulator Choose how far stocks and bonds fall and see what it means in euros.
Emergency fund calculator See how many months it takes to set aside a buffer of the size you choose.
Reach a target amount How long it takes, or which monthly amount it takes, to reach a target at a return you choose.
Investment timing Compare investing a sum at once with spreading it, or starting now with starting a few years later.
Portfolio mix Split an amount across two to four example ETFs and see the blended ongoing cost (TER) and what it adds up to.
Which tool answers which question
The nine tools share some maths, but each answers a different question. Start with the question you have, not the tool.
ETF Calculator. Question: what do ongoing fund costs take over the years? Useful for anyone comparing funds. Needs an amount, a monthly amount, a return and a TER. It differs from the compounding calculator by including costs, a chart and several funds at once.
Compounding calculator. Question: how does a starting amount plus a fixed monthly amount grow? Useful for seeing the effect of time. Needs a start amount, a monthly amount, years and a return. It has no fund costs; for those use the ETF Calculator.
Compare ETF costs. Question: what does the TER difference between two ETFs add up to? Needs two TER figures plus an amount and years. Unlike the ETF Calculator it keeps to two funds and one comparison.
Purchasing power calculator. Question: what is an amount still worth after some years at an inflation rate you choose? Needs an amount, years and a rate. It says nothing about returns; it only shows the effect of price rises.
Market crash simulator. Question: what would a fall in stocks and bonds mean in euros? Useful for people who want to see a bad year in numbers. Needs an amount, a split between stocks and bonds and a fall or event to apply. It looks at one event, not at growth over time.
Emergency fund calculator. Question: how many months until a buffer of the size you choose is saved? Needs monthly spending, a number of months to cover, what you have and what you add. Unlike the compounding calculator it works toward a buffer, not a growth figure.
Reach a target amount. Question: how long until a target, or which monthly amount reaches it in the years you choose? Needs a target, a start amount, and either a monthly amount or a number of years. It works backwards from the end, where the compounding calculator works forwards.
Investment timing. Question: what is the difference between investing a sum at once and spreading it, or between starting now and starting later? Needs an amount or monthly amount, years and a return. It compares two plans side by side.
Portfolio mix. Question: what does a mix of ETFs cost in total each year? Needs an amount, two to four example ETFs and their shares. It does not look at what the funds hold, so two mixes with the same cost can carry different risk.
How to read all results
Every result is an illustration built from the figures you type in, not a forecast. Returns are never certain, can be negative and vary from year to year, while the tools apply one constant rate. Past performance guarantees nothing. The 6% shown as a default is an illustrative assumption, not a forecast; change it and compare. Tax, transaction costs and your personal situation are not included, and nothing here is advice. Try a low figure and 0% next to your first choice to see how wide the range is.
More explanation about the tools: