Blockchain · 6 min read

EIP-1559 Base Fee vs Priority Fee: How Gas Really Works

After **EIP-1559**, you pay a **base fee** (burned) plus an optional **priority fee** (tip to validators). Total gas = units × (base + priority), capped by your **max fee**.

Step by step

1. Read base fee trend

Base fee moves with block demand—spikes during NFT mints or airdrops.

2. Set priority for speed

Higher priority = faster inclusion when blocks are full.

3. Use max fee headroom

Max fee must exceed base + priority or the tx stalls.

Base vs priority

You cannot remove base fee; priority is the lever for urgency.

  • Base fee: Protocol-set, burned, rises with congestion.
  • Priority fee: Tip to validators; you choose for speed.

Common mistakes

  • Max fee too low during volatility
  • Ignoring L2 for small transfers

FAQ

Why did my tx cost more than estimated?

Base fee rose between estimate and mining.