Three modes, three different questions
The investment calculator answers three questions, and each tab works out its own.
- Forecast - "what happens if I put in this much every month". You set the contribution, the term and the expected return, and get the final portfolio.
- Capital goal - "how much do I need to set aside to reach a million". You set the target and the term, the calculator works out the monthly contribution.
- Passive income (FIRE) - "how much capital do I need to live off the returns". You set the monthly income you want and the return on capital, and get the capital required plus the contribution needed to build it.
What each field means
- Initial capital - what you start with today.
- Monthly contribution - what you add each month. It goes in at the end of the month, after the return is credited.
- Investment horizon - the term in years, from 1 to 40.
- Expected annual return - an average across the whole period. Historically the broad stock market has returned 7-10 % a year in dollars, though individual years can be deeply negative.
- Annual inflation - affects only the "real value": what your future portfolio is worth in today's money.
An example
Starting with 1 000 ₴, adding 200 ₴ a month, 8 % a year, over 10 years:
- your own money paid in: 25 000 ₴
- portfolio at the end: 38 809 ₴
- of which profit: 13 809 ₴
In the first year the growth is 173 ₴; in the tenth it is 2 873 ₴ for the same year. The difference is not that you started contributing more - it is that the accumulated sum is now doing the work. The yearly schedule under the calculator lays this out year by year: contributions, growth, and the balance at the end of each one.
Goals and passive income in numbers
To reach 1 000 000 ₴ in 10 years at an 8 % return starting from 1 000 ₴, you need to set aside 5 454 ₴ a month.
To live on 20 000 ₴ a month from capital returning 5 % a year, you need 4 800 000 ₴. The formula is simple: annual income divided by the rate. Which is exactly why the withdrawal rate matters so much - at 4 %, the same income needs 6 000 000 ₴.
Why inflation eats more than it looks
That same 38 809 ₴ portfolio, ten years out with 10 % annual inflation (consumer price inflation per the NBU, October 2026), is worth about 14 962 ₴ in today's money. Nominally you are ahead; in real terms you are behind: an 8 % return against 10 % inflation is a real rate of -1.82 %. The 13 809 ₴ of profit is not enough to catch up with prices - your contributions lose purchasing power year after year.
This is not a bug in the calculator. It is the reason long horizons are judged on real returns rather than nominal ones.
What the calculator leaves out
It assumes the same return every year. Real markets do not work that way: the order of good and bad years changes the outcome, especially when you contribute along the way. Taxes on investment income, broker fees and fund charges are not included either.