What is dollar cost averaging?
Dollar cost averaging (DCA) means buying a fixed dollar amount of an asset on a fixed schedule, no matter what the price is doing. $50 every Monday buys a lot of Bitcoin when Bitcoin is cheap and a little when it's expensive, so your average cost per coin drifts below the simple average of the prices you bought at. That's not a trick — it's arithmetic, and it's the reason DCA is the default advice for anyone who doesn't want to time the market.
The thing almost nobody does is check the actual numbers. "Just DCA" is repeated constantly, but the outcome depends enormously on when you started and what you bought. Someone who started weekly Bitcoin buys in 2017 and someone who started in 2021 had wildly different experiences with exactly the same discipline. This calculator exists so you can look at the real history instead of the slogan.
How this calculator works
It uses real daily closing prices from Coinbase's public market data — Bitcoin from 20 July 2015, Ethereum from June 2016, Solana from June 2021 — through to the most recent close. On every scheduled buy date it does the obvious thing: divides your contribution by that day's close and adds the coins to the pile. There are no fees, no slippage and no tax modelled, so treat the result as the optimistic ceiling; a real exchange charging 0.5% per buy would shave roughly half a percent off your accumulated coins.
What each number means
- Total invested — contribution size × number of buys. Money that actually left your bank account.
- Coins accumulated — the sum of every fractional purchase.
- Average cost basis — total invested ÷ coins accumulated. This is the number to compare against today's price: if the current price is above your basis, the position is green.
- Return — profit ÷ invested. Note this is a total return, not annualised; a 200% return over eight years is a very different animal from 200% over one.
- Lump sum instead — what the same total amount of money would be worth if you'd put it all in on day one. Usually the honest comparison people avoid.
DCA vs lump sum: which actually wins?
Run the comparison above on almost any long Bitcoin window and you'll see lump sum ahead. That's expected, and it isn't an argument against DCA. In an asset that trends up over the period you measure, money that goes in earliest compounds longest, so front-loading wins on average. Studies on equities put lump sum ahead roughly two-thirds of the time for exactly that reason.
Three reasons people still choose DCA anyway, and all three are legitimate:
- You don't have the lump sum. Most people are investing income as it arrives. The comparison is academic — you literally cannot deploy in January money you won't earn until August.
- Regret risk is real risk. Putting your entire savings into Bitcoin on a single day and watching it fall 60% is how people sell at the bottom and never come back. A strategy you abandon has a return of zero.
- Entry timing dominates lump sum results. Lump sum wins on average and loses badly at peaks. Set the start date to November 2021 above and compare — that's the scenario DCA is insurance against.
Daily, weekly or monthly?
Change the frequency toggle and hold everything else constant. You'll find the difference between daily, weekly and monthly buying is remarkably small — usually a fraction of a percent over multi-year windows. Frequency is close to noise; the two variables that actually move the outcome are how long you keep going and how much you contribute.
So pick the frequency you'll actually stick to, and let fees decide the tie-break. If your exchange charges a flat fee per trade, daily buying of small amounts is genuinely bad — 30 fees a month instead of one. If fees are a percentage, frequency doesn't matter and weekly is a fine default because it lines up with how most people are paid.
Five mistakes this calculator will show you
1. Backtesting only the good window
Starting your test in 2015 makes any Bitcoin strategy look like genius. Run at least one window that begins at a cycle top (November 2021 or December 2017) before you trust a number.
2. Confusing total return with annual return
Divide roughly by the number of years to sanity-check. A headline 400% over nine years is about 20% a year — excellent, but not the lottery ticket the big number implies.
3. Ignoring fees and spread
This model is fee-free. At 1% per buy — not unusual on beginner-friendly apps — a decade of weekly buying quietly hands over about 1% of everything you ever contributed. Use a venue with low maker fees or a free recurring-buy product.
4. Assuming DCA protects you from the asset
DCA smooths your entry price. It does not make a falling asset rise. If a coin goes to zero, disciplined weekly buying gets you to zero too, just more slowly.
5. Stopping during the drawdown
The buys that produce the outsized results are, without exception, the ones made when the chart looked awful. Set the start date to a bear market above and look at how many coins that period bought per dollar.
Frequently asked questions
Is this Bitcoin DCA calculator free?
Yes. The calculator, the chart, the year-by-year table and all three assets are free with no signup and no account. The optional $9 Pro unlock adds a CSV export of every individual contribution and a side-by-side comparison across all three assets.
Where does the price data come from?
Daily closing prices from Coinbase's public market data API, covering Bitcoin from 20 July 2015, Ethereum from 1 June 2016 and Solana from 17 June 2021. Prices are embedded in the page so it loads instantly and works offline.
Does it include exchange fees or taxes?
No. Results assume you bought at the daily close with zero fees, which makes them a best case. Subtract your venue's fee rate — typically 0.1% to 1.5% per buy — for a realistic figure, and remember that selling is usually a taxable event where you live.
What if my start date is before the asset existed?
The calculator clamps to the earliest date it has real prices for and tells you. Bitcoin data begins in July 2015; anything earlier has no reliable exchange close to reference.
Is dollar cost averaging better than buying all at once?
Historically, lump-sum investing beats DCA around two-thirds of the time in rising markets, because earlier money compounds longer. DCA wins when you buy into a peak, and it wins in practice for anyone investing a paycheque rather than a windfall. Use the "lump sum instead" figure above to test both on your own dates.
How much should I dollar cost average into Bitcoin?
This is a calculator, not financial advice, and the honest answer is: an amount whose total loss would not change your life. The useful exercise is to set the contribution to a number you can sustain for five years without stopping, because duration is what actually produced every good result in the table above.