LOC (Lines of Code) pricing is a common methodology for estimating smart contract audit costs. Rather than charging a flat project fee, auditors calculate cost based on the complexity and volume of code to be reviewed. This approach provides transparency and allows projects to understand how scope directly impacts pricing.

Typical Pricing Ranges

What Counts as a "Line"

LOC pricing typically counts:

• Logic lines: Function implementations, conditionals, loops
• Weighted by complexity: A reentrancy guard is simpler than a custom AMM formula

Not typically counted:

• Comments and documentation
• Import statements
• Empty lines
• Interface definitions (unless being audited)

Example Calculation

1Contract: 1,200 SLOC (Solidity Lines of Code)
2Complexity: Medium (DeFi lending)
3Rate: $35/line
4
5Estimate: 1,200 × $35 = $42,000

Advantages

Transparency: Clients understand exactly what drives cost.

Scope clarity: Adding features = adding lines = adding cost.

Comparison: Easier to compare quotes across auditors.

Limitations

Not all lines equal: A 10-line function can be trivial or extremely complex.

Doesn't capture context: Integration risks, deployment complexity, and upgrade patterns aren't reflected.

Gaming potential: Code can be compressed or expanded artificially.

Industry Standards

Most professional auditors use LOC as a starting point, then adjust for:

• Protocol complexity
• Time constraints
• Previous audit history
• Integration risk
• Team responsiveness

LOC pricing provides a baseline, but experienced auditors always factor in the full security context beyond raw line counts.