Savings goal calculator
Estimate the regular contribution needed for a target.
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 the contribution per period needed to reach a target within your selected duration. This solves under fixed duration and return assumptions; it does not predict a future achievement date.
Step by step
- Set the principal, duration, return, contribution frequency and timing, then enter a target. The target uses the currency selected for each scenario.
- Calculate to see both the projection for your current contribution and the contribution needed for the target. The required amount is not automatically applied to the input.
- Use Apply required contribution and recalculate to view the target scenario’s table and chart. The full calculated precision is applied; rounding is for display.
What to look for in these results
The required contribution is for each selected period. Do not read a quarterly payment as a monthly payment. When dividends are paid in cash, the target total includes both portfolio value and accumulated cash dividends.
Questions about this tool
Why is the required contribution zero?
Under the assumptions, the principal’s final total already meets or exceeds the target without extra payments. This does not guarantee that the target will actually be achieved.
Why can the required contribution differ from what the chart implies?
The required contribution is a solution for the target, while the table and chart use the current contribution input. Apply and recalculate to use the solution. Manually entering the rounded displayed amount may introduce a small difference.
Is the target saved in the JSON backup?
Version 1 of the JSON backup stores investment scenarios, not the target. Enter the target again when needed. Importing on this page recalculates against the target currently entered here.
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)