Satoshi Converter

Bitcoin Unit Relationships

BTC, mBTC, μBTC and sat are fixed ways to express a Bitcoin amount. One BTC equals 100,000,000 sats; one mBTC equals 100,000 sats; one μBTC equals 100 sats. Market price does not affect these ratios. Selecting another unit changes the decimal placement and label, not the underlying amount.

The satoshi, usually shortened to sat, is the smallest whole unit this converter accepts. For its history and everyday use, read What Is a Satoshi?. Every valid entry is first resolved to an integer number of sats, then displayed in the chosen destination unit. This makes the satoshi the common reference even when neither selector currently shows sat.

Unit choice is practical. A balance of 0.25 BTC may be easier to scan than 25,000,000 sats, while a small price may read more clearly in sats. mBTC moves the BTC decimal three places, so that balance can also be written as 250 mBTC without gaining or losing precision. Neither notation is more accurate; the useful one is the form the reader or destination expects. Software defaults can still cause serious mistakes: 500,000 sats is 0.005 BTC, whereas 500 mBTC is 0.5 BTC. Check the unit beside both numbers before using a result.

One microbitcoin, written μBTC, is commonly called one bit and equals 0.000001 BTC or 100 sats. Because “bit” also means a binary digit in computing, the interface uses the unambiguous μBTC symbol. For protocol and transaction context beyond denomination conversion, use the Bitcoin reference page.

Why One Extra Decimal Fails

0.00000001 BTC equals 1 sat. Add one decimal place and 0.000000001 BTC equals 0.1 sat. Both strings are valid decimal notation, but only the first can be represented as a whole satoshi. The converter rejects the second instead of changing it to zero or one sat.

Syntax and representability are separate checks. A string may contain only valid digits and still describe less than one satoshi. BTC supports eight meaningful decimal places here because the eighth place is one sat; mBTC supports five, μBTC supports two, and sat input must be an integer. Accordingly, 0.00001 mBTC and 0.01 μBTC pass, while 0.000001 mBTC and 0.001 μBTC fail. These limits are one boundary viewed through four scales.

Trailing zeros do not add value. The input 1.000000000 BTC remains 1 BTC because the ninth digit is zero, while 1.000000001 BTC would require 100,000,000.1 sats. Insignificant trailing zeros are removed before the boundary check, so written precision is not confused with actual value. Grouping has its own syntax rule: 1,000 and 12,345 are accepted, but 10,00 and 12,34,5 are left unchanged for correction rather than interpreted by guesswork.

This boundary matters when an amount comes from a spreadsheet, exchange export or another calculator. Silent rounding would alter the submitted value, so a sub-satoshi remainder is reported directly while the original text remains available to correct. Negative values and exponent notation such as 1e-8 also receive plain-language errors; a period remains the decimal separator. Separating format errors from representability errors tells the user whether to repair the notation or choose an amount that resolves to whole sats. A clean decimal can therefore fail for value precision even when every character is valid.

How the Calculation Stays Exact

Ordinary binary floating-point arithmetic can approximate short decimal values even when the number looks unchanged on screen. This converter instead reads decimal text, applies the selected unit scale and builds one integer satoshi amount. The browser provides immediate updates and the server handles the no-JavaScript fallback with matching scale and validation rules. Both reject fractional sats rather than repairing them. The calculation disclosure shows the active formula, integer value and precision result without exposing internal diagnostic codes.

1. Read and validate the decimal text
2. Build one whole-satoshi amount
3. Format the selected result unit
4. Copy, swap, or compare equivalents

Worked Conversions

Each example passes through a whole-satoshi amount. The operation exposes the unit scale, and the result follows the live converter’s display formatting. Grouping commas make large values easier to read but are omitted from copied numeric output.

Match the To unit to the destination field. If a wallet asks for BTC, select BTC instead of copying a sat value and moving the decimal manually. If an invoice uses sats, select sat so the intended integer is explicit. Swap carries the current result into the source side for a reverse check. This keeps the conversion direction visible and avoids treating a display comma as part of the numeric value.

Input length is bounded to protect the page from accidental oversized strings, not to certify that every accepted number could exist within Bitcoin’s supply. The boundary is operational: it prevents an unexpectedly long field from consuming unnecessary browser or server work. Zero is valid because it remains exactly representable. Negative amounts remain outside this denomination converter’s purpose and are rejected before conversion.

sat, sat/vB and msat

A sat is an amount of bitcoin. sat/vB is a fee rate measured in satoshis per virtual byte. A fee rate needs a transaction’s virtual size before it becomes a fee amount, so 10 sat and 10 sat/vB are not interchangeable. Network demand can change an appropriate fee rate, while denomination ratios stay fixed. See the Bitcoin transaction fee guide for that separate calculation.

A millisatoshi, or msat, is one thousandth of a satoshi used in Lightning accounting. It can be meaningful inside a Lightning system even though it falls below this converter’s whole-satoshi boundary. Lightning implementations may track msats internally before settlement, but that does not make a fractional sat an on-chain output value. Supporting msat would require a different scale and validation model, so an msat balance is not silently mixed into on-chain denomination results.

This tool converts fixed Bitcoin denominations; it does not fetch prices, inspect wallets or estimate network fees. Its output depends only on the visible amount and selected units. Before using a result, confirm whether the receiving field expects BTC, sats, a fee rate or a Lightning unit. Other fixed-unit tools remain available in the converters directory.