smom-dbis-138/docs/guides/GAS_FEE_CALCULATIONS.md

# Gas Fee Calculations for Mainnet Deployments

## Overview

This document calculates the gas fees required to deploy CCIP WETH bridge contracts on Ethereum Mainnet using **conservative estimates** based on MetaMask and Etherscan gas prices.

**Important**: These gas fees are **ONLY for the bridge contracts**, not the WETH contracts:
- **WETH9 and WETH10 on Mainnet**: Already exist (deployed years ago) - **NO deployment needed**
- **WETH9 and WETH10 on ChainID 138**: Predeployed in genesis.json - **NO deployment needed**
- **Bridge contracts**: NEW contracts that need deployment on BOTH chains

## Conservative Gas Price Calculation

**Method**: 2.5x the highest gas price between MetaMask and Etherscan estimates

**Formula**: `Conservative Gas Price = MAX(MetaMask Gas, Etherscan Gas) × 2.5`

**Current Analysis**:
- Highest (MetaMask/Etherscan): .155444001 gwei (from Etherscan)
- **Conservative (2.5x)**: .388610002 gwei
- **Last Updated**: 2025-11-13 05:49:03 UTC

> **Note**: Run `./scripts/deployment/get-conservative-gas-price.sh` to get the latest conservative estimate.

## Contracts to Deploy

1. **CCIPWETH9Bridge** - Bridge for WETH9 cross-chain transfers
2. **CCIPWETH10Bridge** - Bridge for WETH10 cross-chain transfers

## Gas Calculation Formula

```
Total Gas = Base Transaction Gas + Constructor Gas + (Contract Size × Gas per Byte)
```

Where:
- **Base Transaction Gas**: 21,000 gas
- **Constructor Gas**: ~50,000 gas (approximate, depends on constructor logic)
- **Contract Size**: Size of deployed bytecode in bytes
- **Gas per Byte**: 16 gas per byte of contract code

## Contract Sizes

Based on compiled contracts:

| Contract | Size (bytes) | Code Gas | Constructor Gas | Base Gas | Total Gas |
|----------|--------------|----------|-----------------|----------|-----------|
| CCIPWETH9Bridge | ~12,000 | 192,000 | 50,000 | 21,000 | ~263,000 |
| CCIPWETH10Bridge | ~12,000 | 192,000 | 50,000 | 21,000 | ~263,000 |
| **Total** | **24,000** | **384,000** | **100,000** | **42,000** | **~526,000** |

## Conservative Cost Estimates

### Current Conservative Gas Price: .388610002 gwei (2.5x highest)

**Calculation**: MAX(MetaMask Gas, Etherscan Gas) × 2.5

| Contract | Gas | Cost (ETH) | Cost (USD @ $2,500/ETH) |
|----------|-----|------------|-------------------------|
| CCIPWETH9Bridge | ~263,000 | ~0.0001022 ETH | ~$.2555110000 |
| CCIPWETH10Bridge | ~263,000 | ~0.0001022 ETH | ~$.2555110000 |
| Configuration (4 calls) | ~200,000 | ~0.00007772 ETH | ~$.1943050000 |
| **Total** | **~726,000** | **~0.00028213 ETH** | **~$.7053270000** |

> **Conservative Estimate**: At .388610002 gwei (2.5x of .155444001 gwei), total deployment cost is approximately **0.00028213 ETH ($.7053270000)**.

## Cost Estimates at Different Gas Prices

### At 30 gwei (Low Activity)

| Contract | Gas | Cost (ETH) | Cost (USD @ $2,500/ETH) |
|----------|-----|------------|-------------------------|
| CCIPWETH9Bridge | ~263,000 | ~0.00789 ETH | ~$19.73 |
| CCIPWETH10Bridge | ~263,000 | ~0.00789 ETH | ~$19.73 |
| Configuration | ~200,000 | ~0.006 ETH | ~$15.00 |
| **Total** | **~726,000** | **~0.02178 ETH** | **~$54.46** |

### At 50 gwei (Moderate Network Activity)

| Contract | Gas | Cost (ETH) | Cost (USD @ $2,500/ETH) |
|----------|-----|------------|-------------------------|
| CCIPWETH9Bridge | ~263,000 | ~0.01315 ETH | ~$32.88 |
| CCIPWETH10Bridge | ~263,000 | ~0.01315 ETH | ~$32.88 |
| Configuration | ~200,000 | ~0.01 ETH | ~$25.00 |
| **Total** | **~726,000** | **~0.0363 ETH** | **~$90.75** |

### At 100 gwei (High Network Activity)

| Contract | Gas | Cost (ETH) | Cost (USD @ $2,500/ETH) |
|----------|-----|------------|-------------------------|
| CCIPWETH9Bridge | ~263,000 | ~0.0263 ETH | ~$65.75 |
| CCIPWETH10Bridge | ~263,000 | ~0.0263 ETH | ~$65.75 |
| Configuration | ~200,000 | ~0.02 ETH | ~$50.00 |
| **Total** | **~726,000** | **~0.0726 ETH** | **~$181.50** |

## Total Deployment Cost Summary

### Conservative Estimate (Current: .388610002 gwei)

- Deployment: ~0.00028213 ETH (~$.7053270000)
- Configuration: ~0.00007772 ETH (~$.1943050000)
- **Total**: ~.0003598528 ETH (~$.8996320000)

**Recommended Budget**: .0003385569 ETH (~$.8463922500)

### Minimum (30 gwei, low activity)

- Deployment: ~0.01578 ETH (~$39.46)
- Configuration: ~0.006 ETH (~$15.00)
- **Total**: ~0.02178 ETH (~$54.46)

### Moderate (50 gwei)

- Deployment: ~0.0263 ETH (~$65.75)
- Configuration: ~0.01 ETH (~$25.00)
- **Total**: ~0.0363 ETH (~$90.75)

### High Activity (100 gwei)

- Deployment: ~0.0526 ETH (~$131.50)
- Configuration: ~0.02 ETH (~$50.00)
- **Total**: ~0.0726 ETH (~$181.50)

## Recommendations

1. **Use Conservative Estimates**: Always use 2.5x the highest gas price for safety margin
2. **Monitor Gas Prices**: Run `./scripts/deployment/get-conservative-gas-price.sh` before deployment
3. **Deploy during low network activity** (typically weekends or off-peak hours)
4. **Have buffer ETH** - Keep recommended budget amount for deployments and configuration

## Real-Time Gas Price Check

You can check current conservative gas prices using:

```bash
# Get conservative gas price (2.5x highest)
./scripts/deployment/get-conservative-gas-price.sh

# Calculate conservative costs
./scripts/deployment/calculate-conservative-costs.sh

# Update all documentation
./scripts/deployment/update-all-cost-estimates.sh
```

## Notes

- Gas prices fluctuate based on network activity
- Conservative estimates use 2.5x the highest gas price between MetaMask and Etherscan
- Actual costs may be lower than conservative estimates
- Consider using Layer 2 solutions for lower costs (if applicable)
- Bridge configuration can be done in separate transactions to spread costs