Portfolio Growth Simulator
Project the growth of your investment portfolio over time. Enter a starting amount, monthly contributions and expected annual return to get a year-by-year investment forecast — including total contributions, growth and final value.
How it's calculated
Monthly Growth = Balance × (Annual Return ÷ 12)End Balance = Start Balance + Growth + Monthly Contributions
Frequently Asked Questions
- What annual return should I use?
- The FTSE All-World index has returned roughly 8–10% a year over the long term, including dividends. After inflation the real return is closer to 5–7%. Use 5–7% for planning. Higher figures produce projections that look impressive and rarely survive contact with reality, particularly over shorter horizons where a single bad year matters.
- Does this account for inflation?
- No. This calculator shows nominal returns, meaning before inflation. To estimate the real return, subtract your expected inflation rate — typically 2–3% — from the annual rate you enter. The distinction matters over long periods. At 3% inflation, money loses roughly half its purchasing power over 25 years, so a nominal projection overstates what the pot will actually buy.
- How important are regular contributions?
- Very important. Contributing regularly means you buy at a range of prices rather than betting everything on one entry point, which is known as pound-cost averaging. It reduces the damage a badly timed lump sum can do. Even modest monthly amounts compound substantially over 20–30 years, because each contribution starts earning from the day it lands.