Why dollar-cost averaging suits an asset like bitcoin
DCA means buying a fixed dollar amount on a schedule regardless of price. Because the amount is fixed, you automatically buy more BTC when prices are low and less when they're high, which lowers your average cost versus buying a fixed quantity. For an asset that routinely swings 50%+ in a year, DCA's real benefit is behavioral: it removes the temptation to time tops and bottoms.
What the growth assumption does — and doesn't — mean
The calculator grows the BTC price smoothly at your chosen CAGR and buys into that rising curve each month. Real bitcoin returns arrive in violent clusters: multi-year drawdowns of 70%+ followed by explosive rallies. A 20% CAGR assumption might match a decade's endpoint while looking nothing like the path. Run the projection at several rates — including 0% and negative — to see the range of outcomes your plan can survive.
Practical DCA details that matter
Recurring-buy fees vary widely — some platforms charge 1%+ on small automatic purchases, which quietly eats a chunk of your first year's gains. Also decide custody up front: coins left on an exchange carry counterparty risk, while self-custody puts backup responsibility on you. Neither is captured in the math here.
How to use this calculator
Set your monthly buy amount, the number of years you plan to keep buying, and an annual growth rate for bitcoin's price. The projection buys a fixed dollar amount into a smoothly rising price each month and reports total BTC accumulated, your average cost per coin, total invested, and projected ending value. Change the growth rate and re-run to see how sensitive the outcome is to an assumption nobody can know in advance.
A worked example
Buy $200 a month for five years — $12,000 invested in total. At a modeled 15% annual price growth you accumulate more BTC early, when the price is lower, and less later, ending with a position worth roughly $17,000–$18,000 depending on the starting price. But run the identical plan at −20% a year and the ending value drops below what you put in. Testing both paths tells you whether you can stomach the plan's worst plausible outcome, which matters far more than admiring the rosy one.