What Is a Satoshi (Sat)?
You don't need to buy a whole Bitcoin. One Bitcoin divides into 100,000,000 satoshis. Understanding sats is how most people actually interact with Bitcoin day-to-day.
The quick answer
1 BTC = 100,000,000 sats
One bitcoin equals one hundred million satoshis
1 BTC
100,000,000 sats
0.1 BTC
10,000,000 sats
0.01 BTC
1,000,000 sats
0.001 BTC
100,000 sats
Why Does Bitcoin Have Smaller Units?
Bitcoin was designed with divisibility in mind. When Satoshi Nakamoto wrote the original code, there was no guarantee Bitcoin would become valuable. Building in 8 decimal places (100 million units per coin) meant the system would stay usable even if the price rose dramatically.
At a price of $100,000 per BTC, one satoshi is worth $0.001 (a tenth of a cent). You can buy a cup of coffee, pay a freelancer, or send money across the world without needing a whole Bitcoin. The satoshi is what makes Bitcoin practical for everyday use at any price level.
The unit is named after Satoshi Nakamoto, Bitcoin's pseudonymous creator, who disappeared from public view in 2011. Nobody has ever definitively proven their identity. The smallest unit of the world's most divisible money carries their name.
How Do You Convert Between BTC and Satoshis?
The math is simple: multiply BTC by 100,000,000 to get sats, divide sats by 100,000,000 to get BTC. Or think of it this way: move the decimal point 8 places.
| BTC amount | Satoshis | USD at $100K/BTC |
|---|---|---|
| 1 BTC | 100,000,000 | $100,000 |
| 0.1 BTC | 10,000,000 | $10,000 |
| 0.01 BTC | 1,000,000 | $1,000 |
| 0.001 BTC | 100,000 | $100 |
| 0.0001 BTC | 10,000 | $10 |
| 0.00001 BTC | 1,000 | $1 |
| 0.000001 BTC | 100 | $0.10 |
| 0.00000001 BTC | 1 sat | $0.001 |
USD values based on $100,000/BTC for illustration. Bitcoin price changes constantly.
What Does “Stacking Sats” Mean?
“Stacking sats” is Bitcoin community shorthand for accumulating Bitcoin gradually over time, typically through recurring purchases. Since most people can't afford 1 BTC at once, they build their holdings one satoshi at a time.
If you buy $50 of Bitcoin every week, you're stacking sats. At $100,000/BTC, that $50 gets you 50,000 sats per week, or 2.6 million sats per year. This approach is called dollar-cost averaging (DCA) and it's the most common way people accumulate Bitcoin long-term.
Stacking sats example: $50/week DCA at $100K/BTC
50,000 sats
Per week
~216,000 sats
Per month
~2.6M sats
Per year
~26M sats
10 years
What Are Millisatoshis and the Lightning Network?
The Lightning Network is Bitcoin's second layer for fast, cheap payments. It uses off-chain payment channels where balances can be tracked to even smaller units: millisatoshis (msats), which are one-thousandth of a satoshi.
You'll never see millisatoshis in your balance, but they matter for routing fee calculations. Lightning fees are typically measured in millionths of a bitcoin per satoshi routed (ppm). At 1 ppm, routing 1,000,000 sats costs 1 sat in fees. These tiny denominations make Lightning ideal for micropayments: paying per article read, per API call, or per second of streaming.
1 BTC
100,000,000 sats
On-chain
1 sat
1,000 msats
Lightning internal
1 msat
0.001 sats
Lightning routing only
How Many Satoshis Will Ever Exist?
Bitcoin's supply is capped at 21 million BTC. Multiply that by 100,000,000 and you get the total satoshi supply: 2,100,000,000,000,000 sats (2.1 quadrillion satoshis). That sounds like a lot, but there are about 8 billion people on Earth. If Bitcoin were distributed evenly, each person would get roughly 262,500 sats. At $100,000/BTC, that's $262.50 per person.
The supply is enforced by every Bitcoin node on the network. No miner, company, or government can create more sats beyond the 21 million BTC cap. The last satoshi will be mined around the year 2140. Until then, new sats enter circulation through the block reward, which halves approximately every 4 years.
21 million
Total BTC supply
2.1 quadrillion
Total sats ever
~262,500
Sats per person (8B)
~year 2140
Last sat mined
Frequently Asked Questions
What is a satoshi?
A satoshi (sat) is the smallest unit of Bitcoin. One Bitcoin equals 100,000,000 satoshis. Just as one dollar equals 100 cents, one Bitcoin equals 100 million sats. The unit is named after Satoshi Nakamoto, Bitcoin's pseudonymous creator. When the Bitcoin price is high, most everyday transactions are measured in sats rather than whole BTC.
How many satoshis are in one Bitcoin?
There are exactly 100,000,000 (one hundred million) satoshis in one Bitcoin. This is fixed in Bitcoin's code and cannot be changed. The divisibility was designed to allow micropayments even if Bitcoin's price rises to very high levels.
What is the value of 1 satoshi in USD?
The value of 1 satoshi changes constantly with Bitcoin's price. At $100,000 per Bitcoin, 1 satoshi is worth $0.001 (one-tenth of a cent). At $50,000 per Bitcoin, 1 satoshi is worth $0.0005. To calculate: divide the current Bitcoin price by 100,000,000.
What does "stacking sats" mean?
Stacking sats is Bitcoin community slang for accumulating Bitcoin through regular purchases, usually via dollar-cost averaging. Since most people can't afford a whole Bitcoin, they buy fractions , measured in sats. 'Stack sats, not fiat' is a common phrase meaning to save in Bitcoin rather than in government currency.
What is a millisatoshi?
A millisatoshi (msat) is one-thousandth of a satoshi, used only in the Lightning Network. Since Lightning payments route through off-chain channels, they can handle amounts smaller than the minimum on-chain Bitcoin unit. You'll see millisatoshis in Lightning fee calculations and payment routing, but they never appear in on-chain transactions.
Can I buy less than one satoshi?
No. A satoshi is Bitcoin's minimum divisible unit on-chain. You can't send or receive a fraction of a satoshi in a regular Bitcoin transaction. Lightning Network routing uses millisatoshis internally, but those don't appear in your wallet balance. Most exchanges let you buy any dollar amount of Bitcoin, which they express as a decimal fraction down to 8 places (e.g., 0.00001234 BTC).
Why is Bitcoin divisible to 8 decimal places?
Satoshi Nakamoto designed Bitcoin with 8 decimal places (100 million sats per BTC) to ensure usability at any price level. If Bitcoin became very valuable (e.g., $1 million per coin), 1 satoshi would still equal just $0.01, making everyday payments possible. The 8 decimal places were a deliberate design choice for long-term scalability.
What is the smallest amount of Bitcoin I can send?
The minimum on-chain Bitcoin transaction amount is technically 1 satoshi, but in practice the minimum is higher because of transaction fees. If fees are $2 and you try to send 1 sat (worth a fraction of a cent), the fee would be many times larger than the amount. Most wallets enforce a minimum send amount of 546-1000 sats (called the 'dust limit') to prevent economically irrational transactions. On Lightning, you can send tiny amounts for fractions of a cent in fees.
Is satoshi the only sub-unit of Bitcoin?
Satoshi is the base unit (1 sat = 0.00000001 BTC). Other informal units exist: 1 microbitcoin (bit) = 100 satoshis = 0.000001 BTC. These aren't officially standardized but are sometimes used for readability. The community has largely converged on satoshis as the standard denomination for small amounts.
How do I convert between BTC and satoshis?
To convert BTC to sats: multiply by 100,000,000. Example: 0.001 BTC = 100,000 sats. To convert sats to BTC: divide by 100,000,000. Example: 50,000 sats = 0.0005 BTC. A quick mental shortcut: move the decimal point 8 places.
Ready to Stack Sats?
The easiest way to accumulate sats is a recurring DCA purchase on a Bitcoin exchange with auto-withdrawal to cold storage.