Gas Fee Market: EIP-1559 Mempool Simulator

Network Conditions

Network demand 50%

Blocks per second 1.0×

Your Wallet Transaction

Max fee cap 40 gwei

Priority tip 2 gwei

No transaction submitted yet.

Live Market State

Base fee

20.0 gwei

Last block fullness

Mempool pending

0 txs

Blocks mined

How it works

This models Ethereum's EIP-1559 fee market — the exact mechanism every mobile wallet (MetaMask, Trust, Rainbow…) reads from when it shows you a "gas fee" estimate before you sign a transaction.

effectiveTip  = min(priorityTip, maxFee − baseFee)   [only if maxFee ≥ baseFee]
gasUsed       = Σ gas of transactions included, highest effectiveTip first,
                until the 30M gas block limit is reached
baseFee(n+1)  = baseFee(n) × (1 + ⅛ × (gasUsed − gasTarget) / gasTarget)
gasTarget     = gasLimit / 2  (blocks aim to run half full on average)

Network demand — how much gas mobile users are competing to spend per block. High demand fills blocks past target, so the base fee compounds upward each block; low demand leaves blocks empty and the base fee decays back down.
Max fee / priority tip — the two numbers your wallet actually submits. A transaction only enters a block if its max fee covers the current base fee; among eligible transactions, miners/validators pick the highest tips first.
The base fee itself is burned, not paid to anyone — only the tip is a reward, which is why bidding a tip above the going rate (not an unlimited max fee) is what actually buys faster inclusion.
The per-block change is mathematically capped at ±12.5%, which is why real gas prices spike gradually over several blocks rather than jumping instantly, even under a demand surge.

base fee: 20.0 gwei

Your transaction High tip (wins block) Low tip (waits)

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.