Calculator Inputs
How to use this calculator
- Enter your savings goal and when you want to reach it.
- Choose whether the goal is in today’s or future dollars.
- Add current savings, monthly deposits, and contribution growth.
- Set return, fees, tax, and inflation to match your assumptions.
- Include other future funding, extra costs, and existing coverage.
- Press Calculate, then export CSV or PDF for records.
Formula used
- Inflation‑adjusted goal: Goal_FV = Goal_Today × (1 + i)^Y (if goal is in today’s dollars).
- Net annual return: r_net ≈ (r − fees) × (1 − tax) (simplified).
- Future value of current savings: FV_current = S0 × (1 + r_net)^Y.
- Growing contribution future value: with monthly compounding and optional growth: FV_contrib = P × ((1+rm)^n − (1+gm)^n) / (rm − gm).
- Shortfall at goal: Shortfall_FV = max(0, Need_FV − Projected_FV).
- Coverage for goal (today): PV_shortfall = Shortfall_FV / (1 + r_net)^Y.
- Recommended coverage: Coverage = max(0, PV_shortfall + Immediate − Existing) × (1 + Buffer).
Goal sizing and timing
A savings goal is strongest when it is dated and measurable. If you target $100,000 in 12 years, you can map deposits and growth against a clear deadline. This calculator treats the goal as a future obligation and asks whether your savings path can still succeed if income stops unexpectedly.
Inflation and goal translation
When a goal is stated in today’s dollars, inflation converts it to the amount you will likely need later. For example, $100,000 with 3% inflation for 12 years becomes about $142,600 at the target date. If you already define the goal in future dollars, inflation is used only for checkpoint comparisons.
Savings growth assumptions
The projection uses a net return estimate that reduces the expected return by fees and a simple tax drag. With 6.5% return, 0.6% fees, and 10% tax on gains, the net annual rate is roughly 5.31%. Current savings grow for the full horizon, while monthly deposits can rise each year using the contribution growth setting.
Insurance gap and buffer logic
The shortfall is calculated at the goal date, then discounted back to today to estimate coverage. Existing coverage reduces the required amount, and immediate needs can be added for debts or final costs. A buffer, such as 10%, helps cover market swings, timing risk, and changing expenses without rebuilding the plan.
Interpreting reports and next steps
Use the checkpoint table and chart to see how savings and the goal move over time, and note when the benefit needed declines as assets grow. Export the CSV for recordkeeping and the PDF for discussions. Update inputs after major life events, then compare the sensitivity range to decide how conservative your assumptions should be. practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically practically
FAQs
1) What does “recommended coverage” represent?
It estimates the lump sum needed today to close the projected goal shortfall, plus optional immediate needs, minus existing coverage, then adds your chosen buffer for uncertainty.
2) Should the goal be entered in today’s or future dollars?
Use today’s dollars when you think in current purchasing power. Use future dollars when you already know the amount you must pay at the goal date.
3) How is the net return calculated?
The tool estimates net return as (expected return − fees) × (1 − tax on gains). It is a planning shortcut, not a substitute for detailed account-level tax modeling.
4) Why does the calculator show a monthly contribution estimate?
It solves for the monthly deposit that would meet the target need, using the same return and contribution growth settings, while holding current savings and other funding constant.
5) What does “benefit needed” at a checkpoint mean?
It is the estimated lump sum required at that year to fund the remaining gap by the goal date, assuming contributions stop and the lump sum compounds at the same net rate.
6) How often should I update the inputs?
Review at least yearly, and after pay changes, new dependents, large debts, or major market moves. Small updates keep the plan realistic and the coverage estimate aligned.
Example data table
| Scenario | Goal (today) | Years | Return / Inflation | Current / Monthly | Existing coverage | Suggested coverage (approx) |
|---|---|---|---|---|---|---|
| A | $80,000 | 10 | 6.0% / 3.0% | $10,000 / $350 | $0 | $55,000 |
| B | $150,000 | 15 | 6.5% / 3.0% | $25,000 / $500 | $25,000 | $60,000 |
| C | $250,000 | 18 | 5.5% / 3.5% | $40,000 / $700 | $50,000 | $95,000 |