Bitcoin · Calculator

Sats accumulator.
How long to reach your Bitcoin goal?

At any price, Bitcoin is divisible to 8 decimal places (1 BTCBitcoin (BTC)The ticker symbol for Bitcoin, used on exchanges and in price quotes.Full definition = 100,000,000 sats). Enter a monthly DCADollar-cost averaging (DCA)Investing a fixed amount on a regular schedule, such as $50 every payday, regardless of price. It spreads out when money enters the market and buys more units when prices are low, but it does not guarantee a better price than investing all at once, a profit or protection against loss.Full definition amount and a sat target to see your timeline at flat price and under different price-growth assumptions.

The question it answersHow long will it take to accumulate a target amount of bitcoin through monthly DCA?

Prices: uses the latest daily Bitcoin close in the site’s own data file, not a live quote; no price service is contacted. Privacy: runs in your browser. What you enter stays on your device unless you copy a share link, which puts your inputs in the link.

Looking for something close? Bitcoin DCA Calculator: a fixed amount every week or month from a chosen start year, priced with daily closes, with a chart, a lump-sum comparison and CSV export. Lump Sum vs DCA Backtest: whether to invest a pot all at once or spread it out, for stocks or Bitcoin.

Worked example: $100/month DCA at $60,000/BTC. Sats per dollar: ~1,667. Sats per month: ~166,700. Target: 1,000,000 sats (0.01 BTC). Time at flat price: ~6.0 months. At 20% annual price growth, the same target takes longer because each month buys fewer sats.

YOUR INPUTS
Fills in from the latest daily close in the site's data file. A price you type is kept in this browser. Clear the field and that close returns the next time the page loads.
Any positive assumption is speculative. The flat-price scenario shows the minimum number of months required.
YOUR TIMELINE
SATS PER MONTH AT CURRENT PRICE
n/a
MONTHS TO TARGET
0
0 years
TOTAL DOLLARS INVESTED
$0
AVERAGE COST BASIScost basisWhat you originally paid for an asset. Used to calculate how much profit (or loss) you made when you sell.Full definition
$0
COMPARISON BY GROWTH ASSUMPTION
CUMULATIVE SATS OVER MONTHS

Methodology: monthly DCA at the chosen price-growth assumption. Target line marks the goal.

Projection, not a promise. The result follows the assumptions you enter. Real results will differ, sometimes by a lot.

How this tool works
  • 1 BTC = 100,000,000 satoshis. You do not need to buy a whole Bitcoin ×DON'T TRUST, VERIFYClaim: 1 Bitcoin equals 100,000,000 satoshis (8-decimal divisibility).Verify at: bitcoin.org FAQ ↗ Source 1 in the list belowHardcoded in Bitcoin Core consensus rules. Each Bitcoin is divisible to 8 decimal places..
  • At flat price: months = target sats / sats per month at current price, rounded up to a whole month. When the division comes out even, the target is reached in exactly that month.
  • At positive growth: the price rises each month by the factor (1 + annual rate)^(1/12), so twelve months compound to exactly the labeled annual rate, and each subsequent monthly DCA buys fewer sats. The simulation iterates month by month until the target is reached.
  • With any growth above 0%, total sats level off at a ceiling. A target at or above that ceiling is shown as "Never" rather than a month count.
  • The minimum timeline is the flat-price scenario. Any price appreciation extends it; any price decline shortens it.
  • Average cost basis = total dollars invested / total BTC accumulated.
  • The price field uses the latest daily close in the site's data file unless you type one or open a share link that carries one. Only a typed or shared price is saved in your browser.
  • This tool excludes exchange fees, network fees, and tax considerations. Fees typically trim sats accumulated by a few percent (a rough site estimate, not a published figure).

Not financial advice.

HOW THIS IS CALCULATED

This tool runs entirely in your browser: no data is sent to any server. The price field fills with the latest daily close in the site's data file each time the page loads: $81,262, the Coin Metrics end-of-day USD price for 2026-09-19 in the site's data snapshot[2]. A price you type is kept in this browser and a price in a share link is used as given; neither is overwritten. An auto-filled price is not saved, so a return visit gets the current price. Clear the field to hand it back to the saved daily close on the next load.

Sats per month = monthly amount × 100,000,000 ÷ price. One bitcoin is 100,000,000 sats in Bitcoin Core's consensus code[3].

  • 0% growth: months = target × price ÷ (monthly amount × 100,000,000), rounded up to a whole month; a quotient that is a whole number is not rounded up. Total invested = months × monthly amount, and the average cost basis equals the price.
  • Positive growth: month 1 buys at the entered price; each later month multiplies the price by (1 + annual rate)^(1/12) and buys again, so the price rises by exactly the labeled rate every 12 months. The loop repeats until the target is reached. Average cost basis = total dollars ÷ total BTC bought.
  • The comparison table reruns the same calculation at 0, 10, 20, 30 and 50%. The chart plots cumulative sats for the selected rate from month 0 to six months past the target month, and at least 12 months. When the target is never reached it plots 600 months to show the curve leveling off. When the chart would run past 600 months, it plots evenly spaced months (no more than about 600 points) so the crossing still shows; each point's cumulative sats come from the closed-form sum (first month's sats × months at 0%, first month's sats × f × (1 - f^-months) ÷ (f - 1) above 0%). An invalid monthly amount or price leaves the chart empty.

With any growth above 0%, the monthly buys shrink geometrically, so total sats level off at a ceiling: first month's sats × f ÷ (f - 1), where f is the monthly price factor. A target at or above that ceiling is never reached, and the tool shows "Never" with the ceiling, rounded down to a whole sat, instead of a month count, and total dollars invested reads n/a (at 10%, $100 a month from $81,262 levels off near 15.6 million sats, so 1 BTC is out of reach). A monthly amount or price of $0, blank or negative shows n/a instead of a result. Exchange fees, network fees, taxes and falling prices are not modeled.

Verify the methodology or inspect the source code in your browser's dev tools.

Where to go from here

Read next

DCA Into Bitcoin

Why DCA outperforms market timing. Historical simulations, DCA vs lump-sum, and how to automate it on River.

Explore further
  • Bitcoin Allocation SizingThe site advocates for Bitcoin but never tells you what percentage to put in it.
  • Bitcoin DCA CalculatorBacktest a fixed Bitcoin purchase every week or month from any start year since 2015, priced with daily closes, with a lump-sum comparison.
  • Satoshi to USD ConverterThree-way converter between satoshis, bitcoin, and US dollars at the current market price.

Sources

Bracketed numbers and verify badges in the text link to these sources. Figures, rates and rules change: check each source’s date before acting on it.

  1. Bitcoin.org, bitcoin.org FAQ ↩
  2. Coin Metrics, Price. Checked 2026-09-26. ↩
  3. Bitcoin Core, src/consensus/amount.h. Checked 2026-09-26. ↩

Calculators are educational estimates, not financial advice. Disclosures · How pages are reviewed