L2 Data Availability Cost Estimator

WHAT IT DOES

The L2 Data Availability Cost Estimator is a DeFi tool that estimates the total cost of L2 transactions including both execution gas and data availability (DA) fees. It takes user-provided transaction data size, L2 gas price (auto-fetched from the connected provider), and DA layer cost per byte, and calculates the total transaction cost. This helps developers and users understand the true cost of L2 transactions, plan gas budgets, and compare costs across different L2 networks.

HOW TO USE

Select your L2 network (Arbitrum, Optimism, Base, or zkSync Era). Enter the expected calldata size in bytes, set the L2 gas price (or use the "fetch L2 gas price" button to auto-fetch), and adjust the DA cost per byte if needed. Click "estimate cost" to calculate the breakdown. The tool displays the gas breakdown (base gas, calldata gas, total L2 gas) and cost breakdown (L2 execution cost, DA layer cost, total cost), along with a visual DA cost share bar and a rough L1 comparison estimate.

TECHNICAL MECHANISM

The tool calculates L2 execution gas as the sum of base gas (21,000) and calldata gas (data size × 16 gas per byte). The L2 execution cost is (total L2 gas × L2 gas price). The DA layer cost is (data size × DA cost per byte). The total cost is the sum of both components. The tool fetches the L2 gas price from the connected provider using getFeeData(), which returns the current gas price in Gwei. The DA cost per byte is user-configurable with a default of 0.005 Gwei, representing typical DA layer costs for rollups that publish data to Ethereum. Results are displayed with a visual breakdown showing the percentage contribution of each component, helping users understand the cost structure of L2 transactions.

WHAT IT CANNOT SEE

The tool cannot accurately predict L2 gas prices without live RPC data. It cannot account for DA layer price fluctuations. The tool cannot estimate costs for specific L2 networks without their gas price oracles. It cannot detect changes in DA layer fee structures without manual updates. The tool cannot predict congestion pricing or base fee changes. It cannot account for L2-specific compression algorithms or variable calldata costs. The tool cannot validate transaction data size without user input. It cannot estimate costs for L2 networks that use alternative DA solutions (e.g., Celestia, EigenDA) without additional data.

PLEASE NOTE

This tool is designed for Ethereum Virtual Machine (EVM) compatible chains and L2 networks that publish data to Ethereum's DA layer. The DA cost per byte is an estimate and may vary between L2 networks. The tool provides estimates only and should be used as a reference for cost planning. Always verify costs on the actual L2 network before executing transactions. The L1 comparison is a rough estimate—actual L1 costs may differ significantly.