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Satoshi to Bitcoin Converter

Convert between Satoshi and Bitcoin denominations

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About This Tool

Converts between satoshis (the smallest Bitcoin unit) and BTC. One bitcoin equals 100,000,000 satoshis; the conversion is a fixed power-of-ten shift. The mBTC (millibitcoin = 100,000 sat) and bit (μBTC = 100 sat) intermediate units are also supported.

The satoshi is named after Satoshi Nakamoto and is the fundamental on-chain accounting unit.

Bitcoin's transaction format stores all amounts as 64-bit signed integers in satoshis. The 100-million-satoshi-per-bitcoin ratio was set in the original 2009 codebase; it gives 21 quadrillion total satoshis once the 21-million-BTC supply cap is reached. The choice was pragmatic: 8 decimal places offer enough granularity to handle micro-payments at any plausible future BTC price while still fitting comfortably in a 64-bit integer with overflow margin. There is no on-chain concept of a 'fractional satoshi'; the consensus rules know only integers.

A worked example: a 0.001 BTC transfer is 100,000 satoshis, also expressible as 1 mBTC. A typical Bitcoin transaction fee at low congestion is 1-10 sat/vByte; for a 200 vByte transaction, that's 200-2,000 sat total fee, or 0.000002 to 0.00002 BTC. At BTC = $60,000, a 1 sat/vByte fee on a small transaction costs about $0.12; during high congestion when fees spike to 200+ sat/vByte, the same transaction can cost $24 or more. Fee-rate awareness is the equivalent of Ethereum's gas-price awareness.

Limitations are mostly about display conventions and Lightning. The mBTC and bit denominations were proposed during 2014-2015 as more readable alternatives to BTC for everyday-sized purchases, but neither achieved widespread adoption. Most exchanges, wallets, and explorers display BTC with 8 decimals or sat as a flat integer, with little use of intermediate units. The Lightning Network uses millisatoshis (10⁻¹¹ BTC) for routing-fee precision, but this finer unit exists only off-chain; settling a Lightning channel onto the base layer rounds to whole satoshis.

Floating-point representation is a real hazard here. JavaScript Number cannot represent 0.1 BTC exactly (the same reason 0.1 + 0.2 ≠ 0.3 in floating point). Using Number for sat-to-BTC conversion at large values introduces rounding error in the final decimal places; production wallet code uses string or integer arithmetic to avoid drift. The tool here uses BigInt for the conversion to preserve exact precision.

The about text and FAQ on this page were drafted with AI assistance and reviewed by a member of the Coherence Daddy team before publishing. See our Content Policy for editorial standards.

Frequently Asked Questions

Why is the satoshi the smallest unit?
Bitcoin's transaction script stores amounts as 64-bit integers in satoshis. There is no smaller on-chain denomination, though Lightning Network uses millisatoshis (1/1000 of a satoshi) off-chain.
What are mBTC and bits?
Intermediate denominations meant to make small amounts more readable. 1 mBTC = 0.001 BTC = 100,000 sat. 1 bit = 0.000001 BTC = 100 sat. Neither is universally adopted.
Will satoshi-only addresses ever exist?
All Bitcoin addresses already operate at satoshi precision; the BTC display is purely a UI convenience. Consensus rules know nothing about decimal points.
Does Lightning use satoshis?
Lightning settles in millisatoshis (10⁻¹¹ BTC) for routing fee precision, but channels open and close on-chain in satoshis. Sub-satoshi balances cannot be enforced on the base layer.
Are there transaction fees on this conversion?
No. The tool performs unit math only. No transaction is broadcast and no exchange takes place.
Why does floating-point matter here?
JavaScript Number cannot represent 0.1 BTC exactly. Using Number for conversions accumulates rounding error in the eighth decimal place. Production wallet software uses integer satoshi math throughout and only formats to BTC at display time.
How many satoshis will ever exist?
21 million BTC × 100,000,000 sat/BTC = 2.1×10¹⁵ satoshis maximum. The supply approaches this asymptotically as block rewards halve every four years; the last fractional satoshi will be mined around the year 2140.
What's a sat/vByte?
A fee-rate measure: satoshis paid per virtual byte of transaction size. Total fee equals sat/vByte × transaction vBytes. SegWit transactions get a discount on witness data, which is why vBytes (virtual bytes) replaced raw bytes in fee accumulating after 2017.
How do I read a Bitcoin balance correctly?
Always check the unit label. Wallet displays default to BTC (8 decimals). Block explorers may show satoshi (no decimals). Lightning wallets often use sat as the default unit. Confusing 0.001 BTC with 0.001 sat is a million-fold error; reading the unit label is mandatory.
Are sub-satoshi denominations possible?
Off-chain only. Lightning Network uses millisatoshis (10⁻¹¹ BTC) for routing fee precision, allowing payments below one satoshi. The base layer rounds millisat balances to satoshi at channel open and close. There is no proposal to add sub-satoshi to the base protocol since 64-bit integer accounting in satoshis already provides ample granularity.