How much should I invest vs. keep in savings?
The amount to invest is not simply the amount left after spending. Savings and investments serve different jobs: accessible money can cover near-term needs, while invested money can pursue longer-term growth but may fall in value when you need it.
What shapes the split
- The financial reserve and other money you may need at short notice.
- Known purchases, repayments or life changes and when they are expected.
- How much the plan contributes each month and how that allocation changes over time.
- The return assumptions and investment mix represented in the plan.
- Your time horizon and ability to accept an uncertain investment value.
Separate near-term access from long-term growth
Start with a baseline allocation, then duplicate the plan and change only how new money is divided between savings and investments. For a future goal, schedule the allocation change from the month it would actually begin.
Review the path to the goal, not only the final portfolio. A higher assumed investment balance later does not replace money that must remain accessible sooner, and keeping more in savings changes the compounding opportunity over time.
Questions worth testing
- Does the savings balance remain sufficient before the next known expense?
- What changes if the investment return assumption is lower?
- Could a gradual allocation change fit the timing better than one permanent split?
- How does each path affect the year you could stop working and the plan’s resilience?
How to read the result
Worthifi illustrates the allocation and return assumptions in your plan. It does not predict market returns, losses, inflation or the timing of an emergency, and it cannot determine your required reserve or suitable investment risk. This is not financial, investment or tax advice.
How it works in the app
Set the savings/investments split, or schedule a dated change to it — a glidepath that shifts more into investments (or back to savings) over time. Compare the compounding difference across the plan's horizon.
- Open Investments → Edit portfolio.
- Adjust the allocation, or add a planned “Change allocation” for a future month.
- Compare net worth and portfolio value across the horizon.
Model this yourself