Smart Contract Gas Optimization Calculator
Calculate gas savings from smart contract optimizations. Compare current vs. optimized gas usage, estimate ROI on development effort, and analyze storage/calldata reduction impact.
About this calculator
This calculator estimates the dollar payoff of optimizing a smart contract's gas usage by comparing current and optimized gas consumption per transaction, then scaling the per-transaction savings by daily transaction volume to project daily, monthly, and annual savings against the development cost of doing the optimization work. Gas savings per transaction come from multiplying the reduction in gas units by the network gas price (in Gwei, converted to ETH) and the current ETH-to-USD price, so the same gas reduction is worth more in dollar terms when gas prices or ETH's price are higher. The calculator also breaks part of the total gas reduction into two named EVM protocol cost categories: eliminating a storage slot (an SSTORE writing a previously-zero slot to a nonzero value) costs a base 20,000 gas under the EVM's SSTORE_SET_GAS constant (defined in EIP-2200 and left unchanged by later gas-repricing EIPs, on top of which EIP-2929's cold-access surcharge can apply), and reducing calldata size saves 16 gas per non-zero byte and 4 gas per zero byte under EIP-2028's calldata gas schedule — this calculator uses a blended 12-gas-per-byte average for the calldata estimate rather than tracking the zero/non-zero byte mix exactly.
Whatever gas reduction isn't accounted for by the storage and calldata estimates is reported separately as Other Optimization Gas — this covers savings from cheaper computation, fewer external calls, or tighter opcode usage that the calculator doesn't model line-by-line, and it's floored at zero so it never implies a negative 'unexplained' contribution. Payback period divides the one-time development cost (hours multiplied by hourly rate) by daily savings to show how many days of the optimized contract's operation it takes to recoup the engineering investment, and annual ROI compares a full year of savings against that same development cost.
Financial Disclaimer
This calculator is for educational purposes only and does not constitute financial advice. Results are estimates based on the inputs provided. Consult a qualified financial advisor before making investment or financial planning decisions.
Inputs
Results
Gas reduction (%)
40%
Figures current as of 2026. Sources: Ethereum Improvement Proposals, EIP-2028: Transaction data gas cost reduction, Ethereum Improvement Proposals, EIP-2200: Structured Definitions for Net Gas Metering
How to Use This Calculator
- Enter Current gas per tx, Optimized gas per tx, and Gas price (Gwei) for the contract function you're optimizing.
- Set ETH price ($), Daily transactions, and Dev hourly rate ($) for the development team.
- Enter Estimated dev hours, Storage slots reduced, and Calldata bytes reduced for the planned optimization work.
- Review Gas reduction (%) and Savings per tx ($) to see the per-transaction impact.
- Use Payback period (days) and Annual ROI (%) to decide whether the optimization work is worth the development cost.
How the result changes with Current gas per tx
| Current gas per tx | Gas reduction (%) |
|---|---|
| 250,000 | 0% |
| 375,000 | 20% |
| 750,000 | 60% |
| 1,250,000 | 76% |
What each input means
- Current gas per tx
- Gas units consumed by the current unoptimized contract function.
- Optimized gas per tx
- Expected gas units after optimization (packing, caching, assembly, etc.).
- Gas price (Gwei)
- Average network gas price in Gwei.
- ETH price ($)
- Current ETH price for USD cost conversion.
- Daily transactions
- Average daily transaction count for this contract function.
- Dev hourly rate ($)
- Cost per hour for Solidity/EVM optimization work.
- Estimated dev hours
- Estimated hours to implement the gas optimizations.
- Storage slots reduced
- Number of storage slots eliminated through packing or removal.
- Calldata bytes reduced
- Reduction in calldata size through tighter encoding.
What each result means
- Gas reduction (%)
- Percentage reduction in gas consumption.
- Gas saved per tx
- Absolute gas units saved per transaction.
- Savings per tx ($)
- USD saved per transaction at current gas and ETH prices.
- Daily savings ($)
- Total daily cost savings across all transactions.
- Monthly savings ($)
- Projected monthly gas cost savings.
- Annual savings ($)
- Projected annual gas cost savings.
- Development cost ($)
- Total cost of the optimization development work.
- Payback period (days)
- Days until gas savings recoup the development cost.
- Annual ROI (%)
- Return on investment for the optimization work over one year.
- Storage optimization (gas)
- Gas saved from reducing storage slot operations.
- Storage Savings ($)
- USD value of the gas saved specifically from eliminated storage slots.
- Calldata Savings ($)
- USD value of the gas saved specifically from calldata size reduction.
- Other Optimization Gas
- Gas saved by the optimization that isn't explained by the storage-slot or calldata reductions above (e.g. cheaper computation, fewer external calls, tighter opcode usage).
How this is calculated
Worked example, using the default values
- Identify Input Parameters9 parametersCurrent gas per tx = 500000, Optimized gas per tx = 300000, Gas price (Gwei) = 30, ETH price ($) = 2000, Daily transactions = 100, Dev hourly rate ($) = 150, Estimated dev hours = 40, Storage slots reduced = 3, Calldata bytes reduced = 200 = 9 input(s) provided
- Calculate Gas reductionGas reduction = (gasReduction / currentGasUsed) * 10040 = 40%
- Calculate Gas saved per txGas saved per tx = currentGasUsed - optimizedGasUsed200000 = 200000
- Calculate Savings per txSavings per tx = currentCostPerTx - optimizedCostPerTx12 = $12
Figures and sources
- EVM calldata gas cost: 16 gas per non-zero byte, 4 gas per zero byte (2026) — Ethereum Improvement Proposals, EIP-2028: Transaction data gas cost reduction
- EVM storage-write gas cost: SSTORE_SET_GAS = 20,000 for a slot written from zero (2026) — Ethereum Improvement Proposals, EIP-2200: Structured Definitions for Net Gas Metering
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does the same gas reduction save more money at some times than others?
Gas savings in dollar terms depend on both the gas price (in Gwei) at the time the transaction runs and the ETH-to-USD exchange rate, not just the number of gas units saved. The same 200,000-gas reduction is worth far more in dollars during a period of high network congestion (high Gwei) and a high ETH price than during a quiet, low-price period, even though the underlying gas savings is identical.
Where do the storage slot and calldata gas cost estimates come from?
They reflect the EVM's own named protocol-level gas cost schedule: writing to a fresh storage slot costs a base 20,000 gas (the SSTORE_SET_GAS constant documented in EIP-2929), and calldata costs 16 gas per non-zero byte versus 4 gas per zero byte under EIP-2028's transaction data gas cost reduction. This calculator uses a blended 12-gas-per-byte average for calldata rather than modeling the exact zero/non-zero byte mix of your specific encoding.
Is a short payback period always a good sign?
A short payback period means the optimization pays for itself quickly, which is generally favorable, but it's worth weighing against opportunity cost — the same developer hours might produce more value working on a different feature or a contract with even higher transaction volume. Payback period tells you how fast the investment recoups itself, not whether it's the best use of the team's time relative to alternatives.
Why does daily transaction volume matter so much to the projected savings?
Every transaction that calls the optimized function benefits from the same per-transaction gas reduction, so total savings scale directly with how many times the function runs. A gas optimization on a rarely-called admin function saves far less in aggregate than the identical optimization applied to a contract's most frequently-called user-facing function, even though the per-transaction gas reduction might be the same.
Does reducing gas usage help even if my contract's ROI on the optimization work is low?
It can still be worth doing for reasons beyond pure ROI — lower gas costs improve the experience for every user who calls the contract, which can matter for adoption and competitiveness even when the raw dollar payback to the DEVELOPMENT team specifically is modest. ROI here measures the return to whoever pays for the engineering work, not the full value delivered to end users.
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