Personal Investment Return Calculator
Find your real, personalised rate of return — accounting for every deposit, withdrawal and its exact date. Unlike broker headline figures, this calculator gives you your true money-weighted (XIRR) annualised return. Works with any ISA, SIPP, dealing account or fund.
What is this and why does it matter?
When your broker quotes "10.4% over the last 3 years", that's a time-weighted return — it measures the fund's performance independently of when you invested. If you put in a large lump sum just before a crash, or drip-fed in during a downturn, your personal experience looks completely different.
This calculator computes your XIRR — the single annualised rate that, applied to every cash flow you've made (with its exact date), produces your final balance. It's the professional standard for measuring what an individual investor actually earned. The Investment Association and CFA Institute both recommend money-weighted returns when the goal is to evaluate an individual's investment outcome rather than a fund manager's skill.
XIRR is particularly relevant for UK investors who contribute to ISAs and SIPPs on an irregular schedule — annual allowance top-ups, one-off pension transfers, or monthly direct debits all affect your personal return. A globally diversified index fund might report 8% annualised over five years, but if you invested 60% of your capital just before a correction, your actual experience could be substantially lower. Conversely, investors who drip-fed during the 2022 downturn and held through the recovery may find their XIRR exceeds the fund's headline number.
This calculator supports manual entry, CSV paste, and file upload — with built-in broker profiles for Hargreaves Lansdown, Vanguard, Trading 212, Freetrade, and AJ Bell. Everything runs in your browser; no data is sent to any server. Your inputs are saved to local storage so you can return and update your figures as your portfolio evolves.
How to use it: Enter your opening investment, log every deposit and withdrawal with its date, then enter your current or closing balance. Hit Calculate. Your true return appears instantly, with a chart and benchmark comparison against the S&P 500, FTSE 100, or FTSE All-World.
| Date | Type | Amount (£) |
|---|
Required format
date,type,amount
2022-03-15,deposit,500
2022-09-01,deposit,250
2023-04-10,withdrawal,150
date — YYYY-MM-DD | type — deposit or withdrawal | amount — positive number, no £ sign. Include header row. You can paste directly from Excel or Google Sheets.
File format — CSV or Excel (.xlsx)
date,type,amount
2022-03-15,deposit,500
2022-09-01,deposit,250
Three columns: date, type, amount with a header row. Date format: YYYY-MM-DD preferred, DD/MM/YYYY also accepted. Excel date cells work too. Max 500 rows. Select your broker above to auto-map column names from broker exports.
Portfolio curve is modelled from your cash flows and XIRR rate — illustrative, not daily valuations.
Understanding Your Personal Investment Return
Most investors never know their true rate of return. They see the fund factsheet quoting 10% per year and assume that's what they've made — but if they started investing in 2021 and put in a large sum just before the 2022 correction, their personal experience looks nothing like the long-run average.
The money-weighted return (XIRR) is the professional standard for measuring individual investor performance. It's the methodology used by the Investment Association and the CFA Institute when the goal is to measure what an investor actually earned — not what a fund delivered in the abstract.
Knowing your real return has practical value: it tells you whether you're on track for your goals, whether your approach to timing the market has helped or hurt you, and whether a simpler strategy — like a monthly direct debit into a passive index fund — might have served you better.
Why XIRR Differs From Time-Weighted Returns
Your broker's headline return is almost always a time-weighted return (TWR). The TWR isolates fund performance by removing the impact of cash flows — it answers "how did the fund do?" rather than "how did I do?" This distinction matters enormously in practice. Two investors holding the same fund over the same period can have wildly different personal returns depending on when they added or withdrew money.
Consider a fund that returns 20% in year one and then loses 15% in year two. The TWR is approximately 2% annualised. But if you invested £50,000 at the start of year one and then added another £50,000 at the start of year two (right before the decline), your XIRR would be negative — because the larger sum experienced the loss. This is the reality XIRR captures that TWR deliberately strips away.
How UK Investors Can Use XIRR Effectively
For UK investors holding assets across ISAs, SIPPs, and general dealing accounts, XIRR provides a single number that captures your total investment experience. It accounts for the timing of ISA allowance contributions each April, lump-sum pension transfers, and ad-hoc top-ups. If you are drip-feeding into a Stocks and Shares ISA through monthly direct debits, your XIRR will typically differ from the fund's reported return because you are buying at different prices throughout the year.
XIRR is also valuable for comparing your own performance across different time periods or accounts. You might discover that your ISA — where you invest passively in index funds — significantly outperforms your dealing account where you trade individual shares. This kind of insight is only possible with a money-weighted return that accounts for your actual cash flow timing.
The benchmark overlay feature on this calculator lets you compare your personal return against the S&P 500, FTSE 100, or FTSE All-World index. While the comparison is approximate (it models a single lump sum at your start date, not your exact contribution schedule), it gives you a useful reference point for whether active decision-making has added or subtracted value compared to a simple buy-and-hold index strategy.
This calculator is for educational and informational purposes only. Results are based on the data you enter and mathematical modelling. This is not financial advice. Investment returns can go down as well as up. Past performance is not a guide to future results. Benchmark overlays use approximate historical annual return data and are illustrative only. Always consult a qualified financial adviser before making investment decisions.