Compare drip-feeding monthly contributions with investing a lump sum on day one
The cash pot compared as lump sum today vs drip-fed monthly.
Existing holdings counted in both strategies from day one.
Interest earned by the DCA cash waiting to be invested. Set 0 for classic cash drag.
DCA invests equal monthly tranches over this window.
By the end of the drip window the market is back on the expected-return path. Only the route there changes.
Extra deposits that arrive later. Invested immediately on both sides so the comparison stays fair.
Your entries are stored in this browser only and restored next time you open the page.
Monthly through the drip-feed window, then yearly to the horizon.
| Period | Lump Sum | DCA Invested | DCA Cash | DCA Total | Leader |
|---|---|---|---|---|---|
| Adjust inputs to see results | |||||
This free calculator compares two ways of putting the same cash to work: investing the full amount on day one (lump sum) versus drip-feeding it in equal monthly amounts (dollar-cost averaging). Add money you already hold, extra lumps that arrive later, a cash rate for uninvested funds, and a market-path preset to see when each approach pulls ahead.
Already-invested holdings and future lump sums are applied to both strategies at the same moment, so they do not tilt the comparison by themselves.
Figures update as you type. The verdict names the leader at the horizon, the gap in currency and percent, and a short reason. The chart plots lump-sum value against DCA total (invested plus cash still waiting). The table is monthly through the drip window, then yearly.
Already invested + Amount to deploy + future lumps
Goal: See the textbook result — lump sum usually leads when prices grind higher, because more money is working sooner.
Lump sum ≈ $20,097 | DCA ≈ $19,468 | Lump sum ahead by ≈ $629
Goal: See when DCA can win — cheaper purchases during a fall, then a recovery before the window ends.
Lump sum ≈ $20,097 | DCA ≈ $21,972 | DCA ahead by ≈ $1,876
Goal: Model a portfolio you already have, a cash pot you are deciding how to deploy, and a second lump that arrives later.
The extra $25,000 and the later $5,000 grow identically on both sides. The gap is still driven only by how the $10,000 pot is timed.
Studies such as Vanguard’s rolling-period work across major markets have found that investing a lump sum immediately outperformed a 12-month DCA schedule in roughly two-thirds of historical windows, because markets rise more often than they fall. That is context, not this calculator’s output. The presets here are stylised paths so you can see the mechanism, not a forecast of the next twelve months.
Not Professional Advice: This calculator is an estimation and educational tool and does not constitute professional financial advice. Actual investment returns vary and past performance is not a guarantee of future results. Consult a qualified financial advisor for advice tailored to your situation.
Assumptions: Both strategies receive the same capital. Invested money follows the selected path during the drip window, then the constant expected return. Uninvested DCA cash earns the cash rate and any residue is swept into the market when the drip ends. No fees, taxes, inflation, bid–ask spreads or contribution holidays are modelled unless you approximate them through the inputs.
Path presets are illustrative: Early dip, late dip and deep drawdown warp prices inside the DCA window and then rejoin the expected-return path. They are not historical sequences and they are not predictions.
Estimation purposes only: Real portfolios experience volatility, changing contributions and behaviour that a single path cannot capture.
Please email all suggestions for improvements and any bug reports to: dcavslumpsumcalc@personalfinances.me, thank you.