How bitcoin units fit together
Bitcoin is divisible to eight decimal places, and the smallest slice has its own name: the satoshi, after the currency's pseudonymous creator Satoshi Nakamoto. Under the bonnet the Bitcoin network only ever counts satoshis; the familiar decimal BTC amounts you see in wallets and headlines are simply a friendlier way of writing the same whole numbers.
Two in-between units are worth knowing. A millibitcoin (mBTC) is a thousandth of a bitcoin, and a bit (also called a microbitcoin or µBTC) is a millionth. To convert sats to BTC, divide by 100,000,000, which is the same as moving the decimal point eight places to the left. To go the other way, multiply by 100,000,000, or just move the point eight places right.
Worked examples
Why this converter counts in whole satoshis
Computers store ordinary decimal numbers in binary floating point, and many innocent-looking values cannot be stored exactly. Ask most programming languages for 0.1 + 0.2 and you get 0.30000000000000004, which is precisely the kind of dust you do not want anywhere near a money calculation. Naive converters that multiply and divide floating point BTC amounts can show a satoshi total that is one or two sats out, or a BTC figure with a phantom trail of 9s.
This tool sidesteps the problem completely. Your input is turned into a whole number of satoshis, and every result is produced by shifting the decimal point through that digit string as text. No decimal arithmetic ever happens, so the answer is exact at every digit whether you type 1 sat or an amount larger than the 21 million BTC that will ever exist.
Safety note: never enter your seed phrase or private keys into any website, including this one. A unit converter only ever needs numbers. Everything on this page runs in your browser and nothing you type is sent anywhere.
Thinking in sats
Small bitcoin amounts read badly in BTC. A coffee-sized payment might be 0.00012 BTC, which is hard to say out loud and easy to misread by a factor of ten. The same amount is simply 12,000 sats, which is why tipping services, Lightning wallets and much of the bitcoin world quote small sums in satoshis, and why regular buyers talk about stacking sats rather than accumulating decimals. Lightning invoices are denominated in sats (and even in millisats internally), so being fluent in the conversion is genuinely useful rather than trivia.
This tool converts between units only. It never shows a live price, so to value an amount in pounds you multiply your BTC figure by whatever price you are working with. Figures are for guidance only and are not financial advice; cryptoassets are high risk and largely unprotected in the UK, so check FCA guidance before acting on any calculation.
Frequently asked questions
How many satoshis are in a bitcoin?
One bitcoin is exactly 100,000,000 satoshis. The satoshi is the smallest unit recorded on the Bitcoin network, named after its pseudonymous creator Satoshi Nakamoto. There is no smaller on-chain unit.
What is 1 satoshi in BTC?
1 satoshi is 0.00000001 BTC, or one hundred-millionth of a bitcoin. To convert any number of sats to BTC, divide by 100,000,000, which is the same as moving the decimal point eight places to the left.
What are mBTC and bits?
A millibitcoin (mBTC) is a thousandth of a bitcoin, which is 100,000 sats. A bit, also called a microbitcoin, is a millionth of a bitcoin, which is 100 sats. They sit between the tiny satoshi and the large whole bitcoin, and this tool shows both alongside the main result.
Why does the tool work in whole satoshis?
Computers store decimal fractions in binary floating point, so values like 0.1 cannot be held exactly and tiny errors creep into arithmetic. Satoshis are whole numbers, so this converter does all its maths on integers and only moves the decimal point as text. The results are exact at every digit.
Does this tool show live bitcoin prices?
No. It converts between units only and never fetches prices or any other data. Everything runs in your browser and nothing you type is sent anywhere. Never enter a seed phrase or private key into any website, including this one; a unit converter only ever needs numbers.