Investment ROI calculator
Model a specific stock optional
The calculator never pulls in prices automatically. You can check the Live price tab, then enter the price you want to model, in the same currency as your investment. No currency conversion is applied. To make sure the live chart finds the right listing, add the exchange prefix, e.g. NSENG:MTNN.
Showing example setups
- Current price
- — Your input
- Expected price
- — Projection
- Estimated profit
- — Projection
- Expected annual growth
- — Assumption
- Number of shares Projection
Your stock · Base case
Nominal
Market data by TradingView · may be delayed
Lines assume a constant growth rate so the scenarios are easy to compare. Real prices rise and fall unpredictably, and none of these lines is a forecast. Chart values are before any tax on selling.
Compare scenarios
Three sets of assumptions you control. "Bear", "Base" and "Bull" are labels for what if cases. They aren't predictions, and none of them is guaranteed.
| Metric |
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Assumptions
These apply to every scenario. Defaults are illustrative. Change them to match your broker and your situation.
Your figures are saved on this device only.
Added at the end of every month, and charged purchase fees each time.
Percentage taken from each purchase, including commissions and levies.
A fixed charge on each buy. It adds up fast with monthly contributions.
On: after-tax dividends buy more shares, fee-free. Off: they're held as cash earning 0%. Set each scenario's yield in the table above.
Withholding tax taken from each dividend before you receive it.
Optional. Applied to (share value − cost) as if you sold everything at the end. Leave at 0 if it doesn't apply to you.
Only used when you switch to today's money below.
Off shows nominal figures: the amount you'd see in your account. On shows what that amount could buy in today's prices.
Off: only whole shares are bought. Leftover money sits as cash earning 0%. Needs a share price.
Where the number comes from
Step by step for the selected scenario, in nominal terms.
| Component | Amount | Relative size |
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Year-by-year table
How this is calculated
The model simulates your holding month by month. These are the rules it follows.
Data sources
The projection uses no live or historical market data. Every price, growth rate and yield comes from you or from the editable defaults, and nothing is converted between currencies. The Live price tab is a separate TradingView chart, shown for reference only. It may be delayed and never feeds into the numbers.
Price growth
The share price compounds monthly at the scenario's annual rate: each month price × (1 + rate)1/12. Real prices don't move smoothly. They can fall sharply even in a "bull" period.
Buying & fees
Your initial amount buys shares at month 0. Monthly contributions buy at the end of each month. Every purchase pays the % fee plus the flat fee. Dividend reinvestment is treated as fee-free.
Dividends
The annual yield is paid in four quarterly instalments on the value of shares held at the time, less withholding tax. The amount is either reinvested or held as cash. Dividends aren't guaranteed, and companies can cut or cancel them.
Taxes
A simplified model: dividend withholding, plus optional tax on gains as if you sold at the end. It ignores allowances, brackets and loss relief, and a loss doesn't create a refund.
Returns & inflation
Total return = (value − total contributed) ÷ total contributed. Annualised return is money-weighted (IRR), so it accounts for when each contribution went in. Today's money divides each amount by (1 + inflation)years at the time it occurs.