Compare investment scenarios
Compare yearly projections for up to three scenarios.
See examples and explanations ↓A nominal, pre-tax simulation. Taxes, fees, and inflation are excluded. Returns are not guaranteed.
Simulation results
Enter your assumptions, then select Calculate.
JSON
Up to 1 MiB (1,048,576 bytes) and 1–3 scenarios. Files stay in your browser. Current work is preserved until you confirm.
What this tool explores
Calculate up to three scenarios side by side. Check their conditions so that a larger contribution is not mistaken for a better return assumption.
Step by step
- Enter scenario A, then select Add scenario. Each added scenario copies A’s inputs; change the assumptions you want to compare.
- Check duration, principal, contribution amount, frequency, timing and currency in the conditions table. Match to A aligns those fields while preserving return, yield and reinvestment assumptions.
- Calculate and read the shared chart and each scenario’s yearly table. Different currencies have no shared money axis; read those results in their own currencies.
What to look for in these results
A higher chart line does not establish a superior real investment. Read assumed returns, dividend treatment, payment conditions and total contributions together. Changing currency relabels amounts without converting them.
Questions about this tool
Can I calculate when conditions differ?
Yes, and differing conditions are identified. Align them to isolate returns, or intentionally keep a payment condition different when that is what you want to explore.
Does importing JSON immediately replace my work?
No. Size, format, version and input ranges are checked before a preview appears. Confirmation replaces inputs and recalculates; cancellation or an error preserves current work.
Calculation method
The annual return is an effective annual rate. Monthly return is (1 + annual return)^(1/12) − 1. Contributions occur at the beginning or end of each 1-, 3-, or 12-month period. Total-return mode already includes dividends, so no additional dividend is added.
Separate-dividend mode assumes a monthly payout of the opening value after any start-of-month contribution × annual yield ÷ 12. After price growth, the dividend is reinvested or held as non-interest-bearing cash, followed by any end-of-month contribution. This does not model real securities’ payout calendars. Values are rounded only for display.
Reading the results
Total gain is portfolio value plus cumulative cash dividends minus initial principal and subsequent contributions. Cash dividends are separate from portfolio value. The goal tool solves for the contribution per period under your assumptions; the target includes cumulative cash dividends.
Limitations and FAQ
Does this predict future returns?
No. This is a simulation with constant assumed returns and yields. It does not predict actual losses or volatility.
Are my inputs stored?
Inputs stay in this page’s memory and are lost when you leave. Download a JSON backup if needed. The operator cannot recover your file.
Calculation version: invest-1.0.0 · Source review date: 2026-10-05. Investor.gov (reference for compound-interest inputs; not a validation of ToffeeLab’s monthly dividend assumptions)