How Many Satoshis Are in a Bitcoin? Sats and Units Explained

Key takeaways

• One bitcoin equals 100,000,000 satoshis. One satoshi is 0.00000001 BTC, the smallest unit recorded on Bitcoin’s main blockchain.
• The name honors Bitcoin’s creator, Satoshi Nakamoto, and “sats” is the everyday shorthand.
• Every unit is a fixed fraction of a bitcoin. A millibitcoin is 0.001 BTC, a bit is 0.000001 BTC (100 sats), and the Lightning Network can count down to a thousandth of a satoshi.
• Converting between bitcoin and sats is a matter of moving the decimal point eight places. Turning either into dollars needs a price, and this article gives none. The Bitcoin unit converter handles the arithmetic with a price you type yourself.
• You do not need a whole bitcoin to own bitcoin. The risk to watch is mixing up units when you send.

How many satoshis are in one bitcoin?

One bitcoin is 100,000,000 satoshis, which is one hundred million. Seen the other way, a single satoshi is 0.00000001 BTC, the eighth digit after the decimal point.

The arrangement is the same one you already know from dollars and cents, only finer. A dollar splits into 100 cents. A bitcoin splits into 100 million satoshis. Bitcoin’s software actually stores every amount as a whole number of satoshis, so the “0.5 BTC” you see on a screen is a display convention for 50,000,000 of them. There is no hidden fraction below that unit on the main chain.

That is why you will see two ways of writing the same balance. A wallet might show 0.00042000 BTC or 42,000 sats. The amounts are identical, and only the format differs. What Is Bitcoin? covers the bigger picture of what these units measure.

What is a satoshi, and why is it called that?

A satoshi is the smallest unit of bitcoin that can be recorded on the main Bitcoin blockchain. It is named in honor of Satoshi Nakamoto, the pseudonym of the person or group that created Bitcoin. Who they were is unknown, and Who Is Satoshi Nakamoto? lays out what is and is not known.

The name is a convention that users adopted, not something the protocol requires. The software only counts whole units, and “satoshi” is the label people attached to that unit. In conversation it is shortened to “sat,” with “sats” for the plural: “I sent 5,000 sats” or “my wallet quotes fees in sats per byte.”

Note that a satoshi is not a separate coin or a token you can hold apart from bitcoin. It is just a small slice of one bitcoin, the way a cent is a slice of a dollar.

What are the other bitcoin units?

Besides bitcoin and the satoshi, two other units appear now and then. The millibitcoin (mBTC) is one thousandth of a bitcoin, and the bit (also written µBTC) is one millionth. All are exact, fixed fractions, so nothing in this table depends on the market.

Unit	Symbol	Value in BTC	Value in satoshis
Bitcoin	BTC	1	100,000,000
Millibitcoin	mBTC	0.001	100,000
Bit (microbitcoin)	bit or µBTC	0.000001	100
Satoshi	sat	0.00000001	1
Millisatoshi (Lightning only)	msat	0.00000000001	0.001

Millibitcoins and bits are less common than sats today, and the word “bit” is used differently by some software, so check what your app means by it. The unit label on screen is the only reliable guide.

How do you convert between bitcoin and satoshis?

To convert bitcoin to satoshis, move the decimal point eight places to the right. To convert satoshis to bitcoin, move it eight places to the left. No price is involved, because you are describing the same quantity in two units.

Some worked examples with invented round amounts:

Starting amount	Converted
0.005 BTC	500,000 sats
0.0123 BTC	1,230,000 sats
250,000 sats	0.0025 BTC
21,000 sats	0.00021 BTC
1,500 sats	0.000015 BTC

Dollars are a different step. To find how many sats one dollar buys, divide 100 million by the price of one bitcoin in dollars, then multiply by the amount you want. The price changes constantly, so the answer does too, and this article quotes none. The Bitcoin unit converter does the whole calculation exactly, in whole satoshis, and lets you type a price of your own choosing, so it never relies on a live feed.

Can you send less than one satoshi?

On the main Bitcoin blockchain, no. A transaction output carries a whole number of satoshis, and one satoshi is the floor. Even that floor is not quite usable, because nodes apply a default policy that refuses to relay transactions creating extremely small outputs, known as dust. The threshold depends on the output type and is a policy setting, not a protocol rule, so this article gives no figure. What Is a UTXO? explains why such tiny outputs can cost more to spend than they hold.

On the Lightning Network, amounts can be finer. Lightning tracks value in millisatoshis, a thousandth of a satoshi, which lets it express tiny payments and very small routing fees. When a channel is settled on the main chain, the balances come out in whole satoshis again. What Is the Lightning Network? explains how that layer works and where its trade-offs lie.

Why do wallets and exchanges show sats?

Wallets and exchanges show sats mainly because whole numbers are easier to read than long strings of zeros. A balance of 4,200 sats is clearer at a glance than 0.00004200 BTC, and it is harder to drop a zero by accident.

There are other reasons. Network fees are usually quoted in satoshis, typically per unit of transaction size, so sats are the natural unit for comparing them. Bitcoin Fees Explained shows how that works. Many Lightning wallets count in sats because the payments are small. And thinking in sats makes the idea of owning part of a bitcoin feel ordinary, which it is.

Mixing up units carries a practical risk. Typing “1000” into a field labeled BTC is not the same as typing it into a field labeled sats, and bitcoin payments are generally irreversible. Read the unit label before you confirm, and send a small test amount first, as How to Buy and Secure Bitcoin recommends.

Do you need a whole bitcoin to own bitcoin?

No. Bitcoin is divisible into 100 million parts, so you can hold any fraction of a coin, down to a single satoshi on the main chain. Most people hold far less than one whole bitcoin.

Two cautions apply to very small amounts. First, an on-chain transaction pays a fee based on its size in data, not on the amount sent, so moving a tiny balance can cost a noticeable share of it. Second, a count of sats says nothing about value until you attach a price. A large-looking number of sats can still be a small amount of money, and a small-looking one can be worth more than you expect, so always check the converted figure before you treat the number as meaningful.

How do satoshis relate to the 21 million limit?

The 21 million cap is a limit on bitcoin, and in satoshis it is just under 2.1 quadrillion. The exact maximum the rules allow is 20,999,999.9769 bitcoin, which is 2,099,999,997,690,000 satoshis.

Counting in satoshis also explains why the total falls slightly short of a round 21 million. Block rewards are paid in whole satoshis, and each halving rounds down any fraction, a detail covered in How Many Bitcoin Are Left to Mine?. The satoshi is therefore not just a convenience for display. It is the unit in which the whole supply schedule is calculated.

This article is educational and not financial advice. If you are deciding how much bitcoin to buy or hold, a qualified financial professional can look at your circumstances. New to all of this? The Start Here path lists the core guides in order.

Where to go next

• Bitcoin unit converter: convert between BTC, millibitcoins, bits and satoshis with exact arithmetic.
• What Is Bitcoin? A Plain-English Introduction: what the units measure and how the system fits together.
• How Many Bitcoin Are Left to Mine? The 21 Million Cap Explained: how the supply schedule is built in satoshis.
• Bitcoin Fees Explained: Exchange Fees vs Network Fees: why fees are quoted in sats and what sets them.