What is the Dollar Cost Averaging?
Dollar cost averaging means investing a fixed amount at regular intervals regardless of price. Because a fixed sum buys more units when prices are low and fewer when high, your average cost per unit ends up below the average price over the period.
Its real value is behavioural: it removes the need to time the market and makes investing automatic, which is why almost every successful long-term investor does it by default through payroll.
Formula & worked example
Average cost = Total invested / total units
Worked example: investing 1,000 a month for 36 months while the price trends from 100 to 140 with volatility along the way. You invest 36,000 and accumulate units at an average cost below the simple average price — because the dips bought more units than the peaks.
How to use this dollar cost averaging calculator
- Enter your regular investment amount and number of periods.
- Set the starting and ending price to define the trend.
- Add volatility — the more the price swings, the greater the averaging benefit.
- Compare against investing everything at the start.
Smart tips
- Averaging helps most in volatile, sideways or falling markets. In a steadily rising market, investing earlier wins.
- Automate it. The main benefit is removing the decision, and manual investing rarely survives a downturn.
- Do not stop during crashes — those are exactly the periods that buy the most units.
- For a lump sum you already hold, investing immediately usually beats averaging it in, though averaging reduces regret risk.
- Combine with a step-up: raising the amount annually compounds the benefit considerably.
Frequently asked questions
What is dollar cost averaging?
Investing a fixed amount at regular intervals regardless of price, which buys more units when prices are low and fewer when they are high.
Does dollar cost averaging beat lump sum investing?
Usually not in rising markets, since a lump sum has more time invested. It does reduce the risk of investing everything at a peak.
Should I stop investing when markets fall?
No — falling markets are when your fixed amount buys the most units. Stopping defeats the entire mechanism.
How often should I invest?
Monthly is standard and aligns with salary. More frequent intervals make almost no difference to outcomes.
Want the theory behind the numbers? Read our investing guides on the Money Blog.
Written by Gurjeet Singh, Sharpen Solutions. Last reviewed 8 Sep 2026. How we check these numbers.