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Lamports, SOL and transaction fees

A lamport is a billionth of a SOL. How Solana prices transactions with base and priority fees, and why a rent deposit is not one of them.

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Solana counts SOL in lamports, named after the computer scientist Leslie Lamport. One SOL is exactly one billion lamports. Balances, fees and rent deposits are all whole numbers of lamports on chain; wallets divide by a billion to show SOL.

1 SOL        = 1,000,000,000 lamports
0.001 SOL    =     1,000,000 lamports
0.000005 SOL =         5,000 lamports   (one signature)

What a transaction costs

A Solana transaction fee has two parts.

  • Base fee: 5,000 lamports per signature in the transaction. Most transactions have one signature, the wallet’s, so the base fee is 0.000005 SOL. Half of it is burned, half goes to the validator that processes the transaction.
  • Priority fee: optional, and set by the sender. A transaction asks for a number of compute units and offers a price per unit in micro-lamports (millionths of a lamport). Validators process higher-paying transactions first when blocks are busy. The priority fee goes entirely to the validator.

The fee payer, usually your wallet, pays both up front, even if the transaction fails. That is why wallets simulate transactions first: a transaction that would fail is better caught before it costs anything.

Compute units

Every instruction uses compute units, Solana’s measure of work. A simple transfer needs a few hundred; a swap through several pools can need hundreds of thousands. A transaction sets a compute unit limit with the Compute Budget program, and the priority fee is that limit times the price per unit. Apps that set a tight limit pay less priority fee for the same price.

Rent is not a fee

Creating an account costs more than its fee: the transaction also moves a rent deposit into the new account. That deposit is not spent. It stays in the account and comes back when the account is closed. Buying a token for the first time, for example, costs a fee of a fraction of a cent plus a deposit for the new token account that you can recover later.

The deposit is set by a formula, explained in How the rent-exempt minimum is calculated, and has been falling since 2026 with SIMD-0437.

Transaction size

A classic Solana transaction can be at most 1,232 bytes, so that it fits into one network packet. Every account address it touches takes 32 bytes, which limits how many instructions fit. A reclaim of many token accounts therefore needs several transactions, each paying its own base fee, and each signed by your wallet.

In short

  • 1 SOL = 1,000,000,000 lamports.
  • Fees: 5,000 lamports per signature, plus an optional priority fee priced per compute unit.
  • Rent deposits are not fees. They stay in accounts and come back when they close.

Before you approve any transaction, it pays to look at what it does, not only what it costs: How to check a transaction before you sign.

Sources

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