CALCULATOR · Finance
Investment Calculator
Project a portfolio from a lump sum plus regular contributions at an expected return — with the inflation-adjusted value in today’s money and the effective CAGR.
Show formula
Method reviewed:Future value with periodic contributions, CAGR, and inflation discounting to real terms · reviewed August 2026
Inputs
Result
Your result appears here
Enter Loan amount and the result fills in as you type.
How it works
- Enter a starting amount and how much you add each period.
- Set an expected annual return and how long you plan to stay invested.
- Add an inflation rate to see the same balance expressed in today’s money.
Frequently asked questions
What does the inflation-adjusted figure mean?
It answers "what would this buy today?". A balance of 500,000 in thirty years at 2.5% inflation buys roughly what 238,000 buys now. Ignoring this is the most common way long projections mislead people.
Should contributions be at the start or end of the period?
End of period is the standard assumption and the safer one. Start-of-period contributions earn one extra period of return each, which raises the final figure slightly — useful if your payments really do land on day one.
Is a constant return realistic?
No, and that is the honest limitation. Real returns vary year to year, and the order in which good and bad years arrive changes the outcome — especially once you start withdrawing. Treat the result as a shape, not a prediction.
Are fees and tax included?
No. Platform fees, fund charges and tax all reduce real-world outcomes. A rough approach is to subtract your total annual charges from the expected return before entering it.
What is the effective CAGR shown?
The compound annual growth rate your money actually achieved across everything you paid in. With regular contributions it is lower than the headline return, because later contributions have less time to compound.
Examples
- 10,000 plus 200 a month for 20 years at 7%
- 144,572.72: 58,000 invested and 86,572.72 of growth, which makes up 59.88% of the final balance.
- The same plan at 2.5% inflation, in today's money
- 88,228.53 — what 144,572.72 in 20 years' time buys at today's prices.
Which of these should I use?
These four run the same future-value arithmetic. What separates them is the question you are asking, not the maths:
- Compound Interest Calculator — you want to see what the compounding itself does — how annual, monthly or daily compounding changes the same rate, and what APY a nominal rate really means.
- Savings Calculator — the money sits in a savings account at a rate the bank quotes you, and you want to know what a fixed monthly deposit turns into.
- Retirement Calculator — the question is not the balance but the income it supports, at a withdrawal rate, on a date you name.
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- Savings CalculatorWork out what a starting balance plus a fixed monthly deposit becomes in a savings account, with interest shown separately from your own deposits.Finance
- ROI CalculatorReturn on investment as a percentage and absolute gain or loss.Finance