Last Updated: 2026-10-26
Risk warning: This is an educational calculation, not an allocation recommendation. A purchase schedule does not protect against an asset becoming worthless, custody failure or an unaffordable cash commitment.
Dollar-cost averaging means buying a fixed cash amount on a schedule. Investor.gov defines the method; it does not certify Bitcoin returns. The useful feature is an explicit contribution rule. Its result can be checked in a ledger of dates, cash spent and units acquired.
Keep two decisions separate
If $100 becomes available from each paycheck, a comparison cannot assume that next month's money was investable today. If $400 is already available, splitting it into four purchases leaves part in cash between purchases. Compare that cash, its interest and its costs too. FINRA explains this distinction and the opportunity cost of waiting. That general discussion is not evidence that a particular crypto schedule outperforms.
A scheduled purchase also differs from an averaging-down bot. A bot may add larger orders after price declines and reserve capital for them. Its maximum commitment can exceed the first order many times. See the separate reserve calculation.
A purchase ledger you can reproduce
These are synthetic prices for one unnamed asset, with no fees in this first calculation.
Scroll sideways to see every column. Keyboard: focus the table region and use the arrow keys.
| Purchase | Cash spent | Price per unit | Units acquired |
|---|---|---|---|
| 1 | $100 | $100 | 1 |
| 2 | $100 | $50 | 2 |
| 3 | $100 | $125 | 0.8 |
| 4 | $100 | $80 | 1.25 |
| Total | $400 | — | 5.05 |
Average acquisition cost is $400 / 5.05 = $79.2079 per unit. The arithmetic average of the four prices is $88.75. A lower acquisition average than that arithmetic mean is a consequence of buying more units at lower prices; it is not a return and does not prove superiority to a competing strategy.
At a final price of $60, the position is worth $303: a $97 loss before costs. A hypothetical $400 purchase at the first $100 price would instead hold four units worth $240. At a steadily rising set of prices, investing the available lump sum earlier can produce the opposite comparison. Specify the price path, dates and available cash rather than declare a universal winner.
Count fees against the right denominator
If a $100 budget includes a 0.1% fee, $99.90 buys the asset and $0.10 is the fee. Fifty-two such contributions cost $5.20 in proportional fees on $5,200 contributed: 0.1%, not 5.2%. At the four prices above, units become 5.04495 if that fee is deducted from each budget. If fees are charged on top, cash paid is instead $400.40 for 5.05 units.
A fixed $1 charge on every $100 purchase is a different cost: $52 on $5,200, or 1%, before any proportional fee. Spreads, conversion, withdrawal and network charges need their own rows. More frequent purchases can increase fixed costs without increasing the proportional rate on fresh contributions.
Define the operating rules before automating
Record the amount, cadence, funding account, fee treatment and maximum total commitment. Decide what happens after a failed debit: skip it, or review it manually. An automatic retry must not silently duplicate a purchase. Keep order IDs, actual filled units, fee currency and transfer records; an order request is not proof of a fill.
Review affordability and asset/custody assumptions when they change. “Never stop buying” is not a substitute for that review. Self-custody changes the risks: backup, address and signing mistakes remain possible. A schedule can simplify a recurring decision; it cannot make the selected asset safe.
Disclosure: The site may earn commissions from links elsewhere. Sources checked October 26, 2026; examples are synthetic and exclude tax.