How it works
Both strategies invest the same total; they differ only in timing. Lump sum puts everything in the market on day one, earning from the start. Dollar-cost averaging (DCA) feeds the money in monthly over a set period, so part of it enters later at whatever prices the market presents. The engine compounds both paths to the same horizon: the lump sum grows for the full period, while each DCA tranche starts growing only when invested. At any positive expected return, lump sum ends higher — the longer money is invested, the more it compounds — and the difference grows with the return. DCA's real value is psychological and path-dependent: if the market crashes right after you invest the full lump, you own the pain at scale; if it drops during a DCA, later tranches buy cheap. History's edge goes to lump sum about two-thirds of the time; DCA's edge is sleeping at night. The calculator shows the expected-value gap; only you know which cost matters more.
Formula
Lump FV = total x (1 + r)^years | DCA: each tranche invested for (years - k) months
Tips
- DCA over 6-12 months is the compromise most people can actually stick with.
- Lump sum is the mathematically better bet on average; DCA is the better bet on your risk tolerance.
- The difference line at 8% over 10 years is roughly 4-6% of the total — small enough to trade for peace of mind.
- Use this tool in reverse at allocation time: the longer your horizon, the more lump sum wins.
Frequently asked questions
- Which is better: lump sum or DCA?
- On average, lump sum wins — studies of historical US markets show it outperforms DCA roughly two-thirds of the time, because markets rise more often than they fall. DCA wins when prices drop during your spreading period, and it wins the psychological game. The calculator quantifies the average gap at your own numbers.
- How long should I spread a DCA?
- Most advisors suggest 6-12 months for a windfall. Longer spreads reduce timing risk further but leave money idle longer, pushing the expected-value gap wider. Very long DCA schedules mostly trade return for comfort.
- Does DCA work in a falling market?
- Yes — that is exactly its moment. Tranches invested at lower prices buy more units, and if the market recovers within your horizon, the lower entry prices lift the final value above the lump-sum path. The calculator assumes a steady return; reality is a path, and DCA smooths it.
- Is DCA the same as a SIP?
- Mechanically yes (regular fixed investments) but strategically no: DCA is a one-time pool being deployed gradually, while a SIP is an ongoing commitment from ongoing income. They share the discipline; they answer different questions.