Investment Calculator for United Kingdom
United Kingdom · GBP. Project an initial balance and regular monthly contributions.
Smarter
Decisions.
Bigger Dreams.
Investment Parameters
£300.00 Minimum £0.00; maximum £500,000.00.
£10,000.00 Minimum £0.00; maximum £100,000,000.00.
5% Minimum 0%; maximum 30%.
20 years Minimum 1 years; maximum 40 years.
Returns compound monthly at the assumed nominal annual rate divided by 12; contributions arrive at month end. Actual returns may vary based on market conditions. This is for illustrative purposes only.
Total Invested
£82k
£82,000.00
Est. Returns
£68.44k
£68,436.50
Total Corpus at Year 20
£150.44k
£150,436.50 · 1.83x wealth multiple
Wealth Growth Over Time
Method and scope
The initial balance compounds monthly at the entered nominal annual rate divided by 12. New contributions arrive at the end of each month. The savings-goal tool solves the same model for the monthly contribution, with a zero-rate limit. Taxes, charges and changing rates are excluded. Enter an assumed rate; investment growth is not guaranteed.
Using this calculator in United Kingdom
Figures are shown in GBP for United Kingdom; selecting another country does not convert an existing investment. Contributions arrive at month end. The entered return is an assumption, not a live local savings rate or a guaranteed investment return. Local tax allowances, account wrappers and charges are not modelled.
Try the starting example
Current balance: £10,000; Monthly contribution: £300; Assumed annual return (nominal): 5%; Years: 20.
Projected balance: £150,436.50.
Compare one assumption at a time
All three rows use the same starting balance, monthly contribution and duration. Only the assumed return changes. The gap is sensitivity to an assumption, not evidence that the higher outcome is more likely. Check the total contributed separately from growth. These fictional scenarios use the starting inputs printed above, not your current entries in the interactive calculator.
| Assumed annual return (nominal) | Projected balance | Interpretation |
|---|---|---|
| 3% | £116,698.15 | One changed input |
| 5% | £150,436.50 | Starting example |
| 7% | £196,665.39 | One changed input |
Are you comparing money available now with money set aside for retirement?
A cash savings goal and a SIPP balance answer different questions. The SIPP model includes basic-rate relief under its stated assumptions, while the savings tool excludes tax and account restrictions. Keep accessible savings separate from a retirement balance when comparing the results.
To reproduce the table, reset the calculator, change only the named input and compare the result and any warning. Record the assumptions with your result. See worked planning examples and our calculation and correction process.
Sources and review date
Rules and method reviewed 2026-11-01. Future changes are not automatically applied. Report a correction.