u64 integers in lamports. Wallets divide by 10⁹ to display SOL. Off-by-one mistakes here are rare on-chain but common in front-end code — the converter sticks to BigInt to keep every conversion exact.1 SOL equals 1,000,000,000 (one billion) lamports. The lamport is the smallest indivisible unit on Solana — named after Leslie Lamport, the distributed-systems researcher whose work underpins much of Solana's design.
Solana split SOL into 10⁹ lamports (a standard SI billion). Bitcoin chose 10⁸ satoshis. Each chain picked its smallest-unit count independently — there's no shared standard across blockchains.
The base fee is fixed at 5,000 lamports per signature — about 0.000005 SOL. Most transactions pay one signature, so the typical cost in SOL terms is tiny. Priority fees on top vary with congestion.
Solana's u64 lamport quantities can exceed JavaScript's safe-integer limit (2⁵³). BigInt arithmetic ensures every conversion stays exact, which matters when you're tracking individual lamports across many accounts.