Regular vs Lump Sum Calculator

This calculator helps you decide whether to invest a lump sum straight away or drip-feed it into the market gradually, a common dilemma after an inheritance, house sale or bonus. You enter the amount you have to invest, your expected annual return, how many months you would spread the drip-feed over, and the total number of years you plan to stay invested. The calculator then projects both approaches to the end of that period and shows you the projected value of investing the lump sum immediately, the projected value of drip-feeding it in over your chosen spreading period, and the dollar difference between the two, along with a plain-language verdict on which comes out ahead. Because the model assumes a steady rate of return, the lump sum almost always wins on paper, since more of your money spends longer in the market. What the numbers cannot show is the emotional and timing risk of investing everything the day before a downturn, which is the real reason many people choose to drip-feed despite the lower expected outcome. Use the tool to see roughly what that peace of mind is likely to cost you in New Zealand dollar terms, then weigh it against your own tolerance for a rocky start. Real returns vary year to year and are never guaranteed, so treat the results as an indicative estimate only, not financial advice.

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This assumes a steady return, so the lump sum, being invested longer, comes out ahead on average. In real markets, drip-feeding reduces the risk of bad timing at the cost of some expected return. Returns are not guaranteed. Estimate only, not financial advice.