Short version: If your scoping doc guesses gas with “average swap = 120k gas,” you’ll miss budgets post‑Dencun. We model opcode‑level costs, L2 data fees (blobs vs calldata), ERC‑4337 overhead, and ZK precompiles up front—so Procurement gets reliable TCO and Engineering gets targets that hold in production.

Title: How We Estimate Gas Costs During the Scoping Phase

Audience: Enterprise product, procurement, and engineering leaders who need SOC2‑aligned estimates, defensible ROI, and a delivery plan that won’t slip when fees or EIPs change.

Pain — The specific headache you’re feeling

• Your SOW says “$0.02–$0.05 per on‑chain action,” but production shows $0.11. Why? That “quick estimate” didn’t account for:

  • Cold vs warm storage reads and the way EIP‑2929 charges for first touches per transaction. (eip.info)
  • Dencun’s blob gas market (EIP‑4844): cheap most days, but volatile during blob congestion events; L2s sometimes even choose calldata over blobs. (eips.ethereum.org)
  • ERC‑4337 validation and pre‑verification overhead when you add passkeys or sponsorship via Paymasters. (erc4337.io)
  • ZK proof verification gas (pairings, not “a lot of gas”): the linear formula after EIP‑1108 repriced BN254 precompiles. (eips.ethereum.org)
  • Deployment‑time costs: initcode metering, code size ceilings, and how they affect migration plans. (eips.ethereum.org)

• Result: “minor variances” become budget write‑ups, Procurement stalls, and launch dates slip.

Agitation — What’s at risk if you keep guessing

• Missed deadlines: You discover close to go‑live that a batched settlement path is 3× more expensive on certain days because blob base fees spiked during a “non‑L2” blob craze, forcing a last‑minute fee strategy rewrite. (blocknative.com)
• Non‑compliant ops: SOC2 auditors ask for deterministic cost envelopes and monitoring; your estimates aren’t explainable at the opcode/EIP level.
• Locked-in overspend: Architecture decisions (e.g., heavy storage vs calldata, lack of access lists, or using SELFDESTRUCT‑based patterns now constrained by EIP‑6780) bloat execution costs you can’t unwind without a refactor. (eips.ethereum.org)
• Vendor churn: RFPs require defensible TCO. “120k gas per call” isn’t defensible when anyone can check the spec sheet.

Solution — 7Block Labs’ estimation methodology (technical but pragmatic)

We front‑load gas economics in scoping so your SOW includes precise, testable targets and Procurement gets ROI math they can sign. The process is deterministic, EIP‑aware, and CI‑enforced.

1. Map the exact on‑chain surface area

• Decompose the user journey into discrete L1/L2 calls: deploy, initialize, write paths, read paths, batched settlements, bridging, and account abstraction flows (if any).
• Tag each step with:
  • Storage footprint (reads/writes), external calls, hashing, signature checks.
  • Chain context: L1 mainnet vs OP Stack/Arbitrum/zk rollups; DA path (calldata vs blobs) and compression.

1. Establish opcode‑level baselines with the current EVM rules

• Warm/cold access pricing (EIP‑2929): first SLOAD = 2100 gas (cold), then 100 gas (warm); cold account access (BALANCE/EXT*/CALL family) = 2600 gas. We enumerate exactly which slots and addresses are first‑touch. (eip.info)
• SSTORE cost and refund behavior: we apply EIP‑2200 math with EIP‑3529’s refund changes and caps; no SELFDESTRUCT refunds remain. (eips.ethereum.org)
• Initcode metering and limits (EIP‑3860): 2 gas per 32‑byte word of initcode and a hard limit at 2× MAX_CODE_SIZE (where MAX_CODE_SIZE=24,576 bytes via EIP‑170); we model deploy costs and flag code‑size risks early. (eip.directory)
• SELFDESTRUCT behavior (EIP‑6780): can no longer rely on it to reclaim storage except in create‑and‑destroy‑same‑tx; we remove refund‑based “gas battery” patterns from scope. (eips.ethereum.org)

1. Model DA (Data Availability) costs post‑Dencun with realistic bounds

• Blob transactions (EIP‑4844) use a separate 1559‑style market with target 3 blobs/block and max 6; we compute “blob gas” envelopes and simulate stress windows. (eips.ethereum.org)
• Reality check on volatility: the first congestion events showed blob base fees can spike orders of magnitude for short bursts—still usually cheaper than calldata, but not always 99.9% cheaper. We include a failover policy (defer posting, switch to calldata, or degrade batch sizes) and budget both paths. (blocknative.com)
• Per‑L2 mechanics:
  • OP Stack fee = L2 execution gas × L2 base fee + (compressed data bytes × blob/calldata price). We parameterize the Ecotone path for blob posting and auto‑switch heuristics. (docs.optimism.io)
  • Arbitrum Nitro’s parent‑chain fee uses per‑tx Brotli estimates and a dynamic data‑unit price; we model the difference between space savings and actual gas savings (zeros are cheaper than non‑zeros). (docs.arbitrum.io)

1. Compression, calldata, and access lists (practical savings you can bank)

• Compression isn’t a flat percentage: we compute cost ratios using the 4/16 gas per byte (zero/non‑zero) rule for calldata; batch shape and entropy matter. (research.arbitrum.io)
• Access lists (EIP‑2930): where storage keys are predictable (e.g., oracles, proxies), we pre‑warm slots and accounts, paying a discounted upfront cost so execution pays 100 gas “warm” reads. We include the intrinsic AL costs in the TCO and only recommend ALs where net positive. (eip.directory)

1. Account Abstraction (ERC‑4337) estimations that survive production

• We budget verificationGasLimit, preVerificationGas, and callGasLimit separately, pull bundler simulations via estimateUserOperationGas, and include Paymaster stake/deposit implications. We track grief‑resistance constraints in validation to avoid DoS‑prone patterns. (erc4337.io)
• If you add WebAuthn (P‑256) signatures, we price the EIP‑7212 precompile (approx. 3450 gas/verify when available) and set a fallback plan where the precompile is absent. (eip.info)

1. ZK verification: no hand‑waving, just pairings math

• BN254 pairing check (post‑EIP‑1108): 45,000 base + 34,000 per pair. We size Groth16 verifiers and aggregated proof verifiers precisely so your “verifyProof()” line item stops being a guess. (eips.ethereum.org)

1. CI‑enforced gas targets, not just spreadsheets

• Foundry gas snapshots: we instrument critical paths with per‑function or intra‑test snapshots (.gas‑snapshot) and set PR gates (tolerance thresholds) so gas regressions fail CI. Your SOW references these gates. (getfoundry.sh)

1. Code‑level patterns we cost and enforce during scoping

• Gas‑first Solidity choices:
  • Prefer calldata over memory for pass‑through byte arrays on L2 (and L1), and avoid storage writes in hot paths unless necessary.
  • Slot packing, fixed‑size structs, and unchecked arithmetic in loops where safe.
  • Use EIP‑1153 transient storage for intra‑tx scratch state instead of SSTORE/SLOAD when applicable. We price TLOAD/TSTORE as warm SLOAD/SSTORE surrogate (~100 gas). (eip.directory)
• Deployment hygiene:
  • Keep constructors lean to avoid initcode expansion charges and code size surprises; plan for library linking vs monolith to respect EIP‑170 while EOF/EIP‑170 changes remain draft. (eips.ethereum.org)

Practical examples (with current specs baked in)

Example 1 — “KYC’d wallet issue + asset mint” on an OP Stack chain using blobs

• Steps:

  1. ERC‑4337 userOp with Paymaster (sponsored) to register a passkey (P‑256).
  2. Mint an asset (ERC‑1155) with metadata hash.
  3. Batch post to L1 via blob.

• Estimation highlights we put in your scope:

  • 4337 validation: signature verify (P‑256 precompile ~3450 gas if available), account validate, optional Paymaster checks; we set verificationGasLimit cap and CI budgets. (eip.info)
  • Execution: warm reads after the first touch (100 gas reads); storage writes priced with EIP‑2200 categories and EIP‑3529 refund caps. (eip.info)
  • DA: compressed payload estimate (bytes after Brotli) × blob gas price, with fallbacks for calldata if blob base fee crosses policy thresholds. (docs.optimism.io)
  • We add a volatility buffer for blob base‑fee spikes observed in real incidents. (blocknative.com)

Example 2 — “ZK proof submit + verify” on L1

• Verify Groth16 with k pairings:
  • Gas ≈ 45,000 + 34,000 × k (BN254). We show k for your circuit (usually 8–14), compute exact verifier cost, and test on a fork to confirm. (eips.ethereum.org)
• If your verifier grew near code size limits, we split libraries and price initcode costs; this prevents a late deployment failure due to EIP‑170/3860. (eips.ethereum.org)

Example 3 — “Cross‑contract read heavy path” on L1 (oracle + proxy)

• Without access list: each first storage/account touch is “cold.”
• With EIP‑2930 access list: pre‑warm targeted addresses/slots; execution uses 100‑gas warm reads. We include the AL intrinsic charges to ensure net savings. (eip.directory)

What goes into your SOW and Procurement package

• Assumptions and bounds:
  • Base‑fee bands for L1/L2; blob base fee percentiles (p50/p90/p99) and a contingency line for “blobscription‑like” spikes. (blocknative.com)
  • Exact opcodes/storage touches per function; cold/warm splits; compression ratios with zero/non‑zero byte sensitivity; ERC‑4337 overhead.
• Monitored KPIs and SOC2‑friendly controls:
  • CI gas gates (fail on >X% drift), on‑chain fee telemetry, blob/calldata switch logs, Paymaster spend limits, and deterministic replay benches.
• Cost‑down roadmap:
  • “Low‑risk” wins we can deliver inside your 90‑day pilot (e.g., access lists, calldata‑first refactors, transient storage), and “medium‑lift” refactors (e.g., splitting hot functions, precompiles adoption plan).

Why the estimates hold (and how we prove it)

• Spec‑correct math:
  • We cite the specific EIPs for cold/warm pricing, refunds, selfdestruct semantics, initcode metering, blob gas rules, and ZK/crypto precompile costs—and embed them in the model. (eip.info)
• L2‑aware DA modeling:
  • We use OP Stack fee formulas and Arbitrum’s documented per‑tx compression accounting, so your L2 line items aren’t “back‑of‑napkin.” (docs.optimism.io)
• ERC‑4337 verification discipline:
  • We estimate via bundler APIs and enforce grief‑resistant validation bounds documented by the spec authors. (docs.safe.global)
• CI enforcement:
  • Foundry snapshots and PR gates make gas a non‑negotiable contract in your repo—not just a PDF. (getfoundry.sh)

Emerging best practices we already apply in scoping (so you don’t pay to learn them later)

• Blob‑aware posting: choose blob vs calldata dynamically with a “max effective $/KB” policy and backoff scheduling during spikes; we prove the threshold with your data. (blocknative.com)
• Data‑first design on rollups: because compressed bytes with many zeros are cheaper, we structure calldata fields to encourage zero‑heavy encodings when safe (bitmaps, packed flags).
• Access list generators: pre‑compute ALs for frequent cross‑contract touches; include or drop per tx based on net benefit as EIP‑2930 charges are not free. (eip.directory)
• Transient storage (EIP‑1153): replace ephemeral SSTORE/SLOAD with TSTORE/TLOAD in pipelines that re‑enter within the same transaction (no persistent state needed). (eip.directory)
• Deployment guardrails: keep constructors small and avoid “mega‑contracts” to respect EIP‑170/3860 while future size changes are still drafts; if you’re near the ceiling, we split and price the links during scope—not during QA. (eips.ethereum.org)

What you get from 7Block Labs (and how it ties to ROI)

• A scoping pack your CFO and SOC2 auditors can sign:
  • Per‑function gas targets with CI gates.
  • DA cost envelopes (blob and calldata) with volatility buffers.
  • ERC‑4337 validation budgets (with/without Paymaster, with P‑256 where supported).
  • ZK verifier gas formulas for your circuits.
• Procurement‑ready TCO and value story:
  • We translate byte‑level savings into “$ per MAU action,” “$ per mint,” or “$ per settle,” with confidence intervals and fallbacks.
• A pilot plan that pays for itself:
  • In the first 90 days, our baseline is cutting 25–60% from the “naïve” gas path using compression‑aware calldata shaping, slot‑warm strategies, and transient storage—without changing your UX or SLA.

Where this plugs into your roadmap

• If you’re launching a tokenized asset workflow or a loyalty/NFT program, start scoping with our dApp and smart contract expertise: see our smart contract development and dApp builds.
  • Explore our smart contract development solutions.
    • https://7blocklabs.com/solutions/smart-contract-development
  • Explore our dApp development solutions.
    • https://7blocklabs.com/solutions/dapp-development
• Planning a new chain integration or migrating to OP/Arbitrum/zk? We handle protocol‑level integration and cross‑chain architecture.
  • See our blockchain integration services and cross‑chain solutions.
    • https://7blocklabs.com/services/blockchain-integration
    • https://7blocklabs.com/services/cross-chain-solutions-development
• Need end‑to‑end delivery with clear ROI? Start with our custom blockchain development services and security audit services to ensure estimates and outcomes align.
  • https://7blocklabs.com/services/blockchain-development-services
  • https://7blocklabs.com/services/security-audit-services

Appendix — A few concrete snippets we drop into scoping

• Gas snapshot guard (Foundry)

# foundry.toml
[profile.default]
optimizer = true
optimizer_runs = 200
gas_reports = ["MyCore","Mint","Settle"]
gas_snapshot_check = true   # fail CI on drift

// t/MyCore.t.sol
import "forge-std/Test.sol";

contract MyCoreGas is Test {
    function test_mint_path_gas() public {
        uint256 g0 = gasleft();
        // call mint(...) with warm slot pattern
        uint256 used = g0 - gasleft();
        // assert budget holds (e.g., < 72_000)
        assertLt(used, 72_000);
    }
}

• Access list example (when predictable keys exist)

// ethers v6, access-list tx
const al = [
  { address: ORACLE, storageKeys: [SLOT_PRICE] },
  { address: IMPLEMENTATION, storageKeys: [SLOT_X, SLOT_Y] }
];

await wallet.sendTransaction({
  type: 1, // EIP-2930
  to: proxyAddress,
  data: callData,
  accessList: al,
  gasLimit
});

• ZK verifier sizing (BN254 pairing count k)

verifyProof() gas ≈ 45,000 + (34,000 × k)
// Example: k=12 ⇒ ≈ 453,000 gas before surrounding logic
// Model includes calldata + hashing + post-verify events.

• ERC‑4337 estimation (bundler)

const gas = await bundler.estimateUserOperationGas({
  userOperation: op, entryPoint: ENTRYPOINT_V06
});
op.verificationGasLimit = gas.verificationGasLimit;
op.preVerificationGas    = gas.preVerificationGas;
op.callGasLimit          = gas.callGasLimit;

Key sources embedded in our model

• EIP‑2929 warm/cold access costs; EIP‑3529 refund changes; EIP‑3860 initcode metering; EIP‑6780 SELFDESTRUCT constraints. (eip.info)
• EIP‑4844 blob market rules; real‑world blob congestion analysis. (eips.ethereum.org)
• Arbitrum and OP Stack L1 data fee mechanics and compression accounting. (docs.arbitrum.io)
• ERC‑4337 UserOperation fields, estimation APIs, and Paymaster security constraints. (erc4337.io)
• EIP‑1108 BN254 precompile repricing (pairing formula). (eips.ethereum.org)
• EIP‑1153 transient storage costs (relative to warm reads/writes). (eip.directory)

Bottom line

• “Gas estimation” during scoping is not a spreadsheet guess—it’s a spec‑driven, CI‑enforced discipline that shields your launch from fee volatility and compliance surprises. If you need estimates that stand up to Procurement, SOC2, and production load, we’ll get you there.

Book a 90-Day Pilot Strategy Call.