Windfall Impact Calculator

It depends on your situation. If you have high-interest debt (credit cards, personal loans), pay that off first — guaranteed return. If you have low-interest debt (mortgage), investing is likely better. Emergency fund shortfall? Top that up. Once those are handled, investing the windfall is generally the highest-impact move for your FIRE date.

Yes — the earlier you invest, the more years it has to compound. A $50k windfall invested at age 30 at 5% real return is worth $216k by age 60. The same windfall invested at 40 is worth $133k. This calculator shows the impact from today.

Any unexpected or one-time lump sum: work bonus, year-end bonus, RSU vesting, stock option exercise, inheritance, gift, insurance payout, tax refund, home sale proceeds, business sale, legal settlement, or crypto gains.

Research consistently shows that lump-sum investing (all at once) outperforms dollar-cost averaging about 2/3 of the time, because markets trend upward over time. If the psychological risk of investing everything at once is too high, a 3–6 month DCA schedule is a reasonable compromise.

Prioritise in this order: (1) Pay off high-interest debt (credit cards, personal loans above 6-7%). (2) Top up your emergency fund to 3–6 months of expenses. (3) Max out tax-advantaged accounts (IRA, HSA) if you haven't already. (4) Invest the remainder in a diversified low-cost index fund portfolio. A $100,000 lump sum invested at 5% real return has roughly 16 years to grow before a typical retirement — it becomes approximately $220,000.

This is one of the most common personal finance questions and it depends on your mortgage interest rate. If your mortgage rate is below 4–5%, investing in a diversified portfolio has historically returned more over time. If your rate is above 6–7%, paying it down is a guaranteed return equivalent to that rate. Most financial planners suggest a hybrid approach: invest if your rate is under 5%, pay down if above 6%, split the difference in between.

Research shows lump-sum investing (investing all at once) outperforms dollar-cost averaging (spreading over 6–12 months) approximately two-thirds of the time, because markets trend upward over time. The downside is psychological — investing everything at once and seeing an immediate market drop is difficult emotionally. If you would lose sleep or sell during a downturn, a 3–6 month DCA schedule is a reasonable compromise that still captures most of the benefit.

At 5% real return, a $50,000 windfall invested today grows to approximately $108,000 in 15 years and $216,000 in 30 years. In FIRE terms, $50,000 invested today could eliminate 1–3 years from your retirement timeline depending on your savings rate. Use the calculator above to see the exact impact on your specific FIRE date — it shows a before/after chart with the years saved.

For most people, a low-cost diversified index fund (like a total market or S&P 500 fund) held in a tax-advantaged account (IRA, 401k) first, then a taxable brokerage account. Avoid trying to time the market — research consistently shows this reduces returns for most investors. If the amount is large enough to feel overwhelming, a fee-only financial advisor (not commission-based) can provide a personalised allocation.