Crypto Unit Converter — BTC, Satoshi, ETH, Gwei & Wei
Convert between denominations where an order-of-magnitude slip is expensive.
1 BTC = 1,000 mBTC = 1,000,000 bits (μBTC) = 100,000,000 satoshi
1 ETH = 1,000,000,000 Gwei = 1,000,000,000,000,000,000 Wei (10¹⁸)
The denominations
| Chain | Unit | Value | Used for |
|---|---|---|---|
| Bitcoin | BTC | 1 | Prices and holdings |
| Bitcoin | mBTC | 0.001 BTC | Rarely used now |
| Bitcoin | satoshi (sat) | 0.00000001 BTC (10⁻⁸) | The base unit. All protocol amounts are integers of satoshis |
| Ethereum | ETH | 1 | Prices and holdings |
| Ethereum | gwei | 10⁻⁹ ETH | Gas prices — always quoted in gwei |
| Ethereum | wei | 10⁻¹⁸ ETH | The base unit. All protocol amounts are integers of wei |
Both chains use integer base units precisely to avoid floating-point error. A balance is never a decimal at protocol level — it is a whole number of satoshis or wei, and the decimal display is a presentation layer.
About
The Crypto Unit Converter performs instant, offline conversions between all denominations of Bitcoin and Ethereum. For Bitcoin: BTC, milli-BTC (mBTC), micro-BTC (bits/μBTC), and satoshi (1 BTC = 100,000,000 satoshi). For Ethereum: ETH, gwei (1 ETH = 1,000,000,000 gwei), and wei (1 ETH = 10¹⁸ wei). All calculations are pure JavaScript — no network request needed.
How to use
- 1 Type any value in any unit field — all other fields update instantly.
- 2 The Bitcoin section converts between BTC, mBTC, bits, and satoshi.
- 3 The Ethereum section converts between ETH, gwei, and wei.
- 4 Use the clear button to reset all fields.
- What is a satoshi and how many are in one Bitcoin?
- A satoshi is the smallest unit of Bitcoin, named after Bitcoin's pseudonymous creator Satoshi Nakamoto. There are exactly 100,000,000 (one hundred million) satoshis in one BTC. Satoshis allow Bitcoin transactions in tiny fractional amounts — useful for micropayments and Lightning Network transactions where the amounts are far too small to express in whole BTC.
- What is gwei and why is it used for Ethereum gas fees?
- Gwei (gigawei) is the unit most commonly used to express Ethereum gas prices. One ETH = 1,000,000,000 gwei (10⁹). Gas fees are quoted in gwei because the numbers are more manageable — "20 gwei" is much easier to read than "0.00000002 ETH". Wei is the smallest indivisible unit (1 ETH = 10¹⁸ wei) and is used in smart contract arithmetic to avoid floating-point errors.
- Why do cryptocurrency units use such small denominations?
- Satoshis, gwei, and wei exist because the base units (BTC, ETH) are worth significant amounts of fiat currency, making fractions necessary for everyday transactions. Without small denominations, you could not send $0.01 worth of Bitcoin or pay a $0.001 gas fee on Ethereum. Small units also allow the protocol to do integer arithmetic without floating-point precision errors.
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