Comprehensive Guide
Learn more in our Investing Guide.
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.