Smart Contract Audit Cost Estimator and Calculator
Quick answer. Multiply auditors by review weeks by a weekly rate, then add premiums and fix reviews. Guardian's main reviews of 1,001 to 2,000 nSLOC took a median 8 working days; Arbitrum's audit proposal cites $10,000 to $40,000 per auditor-week.
Video transcript
Audit firms rarely publish prices. You can still estimate yours from codebase size and public records.
An audit quote is mostly engineer time. Multiply auditors by review weeks by a weekly rate, apply premiums, then add fix reviews.
Review weeks come from 67 Guardian audit reports. Main reviews of one to two thousand nSLOC took a median of eight working days.
Arbitrum's audit proposal cites ten to forty thousand dollars per auditor-week. It calls about twenty thousand not uncommon, so we use that as typical.
With two auditors on EVM code, one to two thousand nSLOC runs about forty-eight to eighty-eight thousand dollars at that rate. Above five thousand, get a scoped quote.
Sherlock, which sells audits, estimates premiums over EVM. Solana adds twenty-five to forty percent, Move or Cairo thirty to forty-five, ZK circuits eighty to one hundred twenty, and a rush twenty to forty.
Arbitrum's 18 completed subsidized audits averaged fifty thousand, seven hundred and six dollars, a rough match for our simple column. For disclosure, Guardian is one of thirteen approved auditors in Arbitrum's program.
This is a planning range, not a Guardian quote. For a firm one, send your repository, commit, files in scope and target date.
Run your own numbers in the full article, then talk to Guardian about a firm quote.
Audit firms rarely publish prices. Sherlock, which sells audits, says most firms and platforms price by nSLOC: non-comment source lines of code.
This estimator turns your nSLOC into a range with a formula you can check. Every number in it comes from a public record linked below.
It is an estimate from public data, not a Guardian quote. Guardian does not publish prices; it scopes each audit from your repository and commit.
How the Formula Works
An audit quote is mostly engineer time multiplied by a rate.
Cost = auditors × review weeks × weekly rate × (1 + language premium) × (1 + rush premium) + fix reviews.
- Review weeks: how long Guardian's published reviews of your size took.
- Weekly rate: $10,000 to $40,000 per auditor-week "depending on the complexity", per Arbitrum's Audit Program proposal.
- Language premium: Sherlock's estimates over an EVM baseline.
- Rush premium: Sherlock estimates urgency adds 20% to 40%.
- Fix reviews: Sherlock estimates $5,000 to $20,000 per pass.
The auditor count is yours to set. Ask each firm how many auditors it staffs, and for how long.
Arbitrum's proposal also says it is "not uncommon" to pay about $20,000 per auditor per week. We use that as the Typical rate.
Review Length by nSLOC
Review weeks come from Guardian's public audit portfolio. We took the 67 onchain reports that record both nSLOC and the dates of the main review.
We counted working days from the first to the last day of that review, leaving out fix reviews.
| nSLOC in scope | Reports | Median working days | Middle half |
|---|---|---|---|
| Up to 500 | 23 | 2 | 2 to 3 |
| 501 to 1,000 | 13 | 4 | 3 to 5 |
| 1,001 to 2,000 | 11 | 8 | 6 to 11 |
| 2,001 to 3,000 | 6 | 11 | 9 to 11 |
| 3,001 to 5,000 | 7 | 14 | 12 to 15 |
| Over 5,000 | 7 | 14 | 11 to 23 |
Sherlock's published timeline guidelines rise with size too: a contest window of about 3 days for 500 nSLOC, 18 for 3,000 and 38 for 6,000.
Limits of the data
- The middle half runs from the 25th to the 75th percentile, rounded to whole days.
- Only 18 of the 67 reports name their auditors, so team size is an input you set.
- 61 of the 67 reviews are Solidity only.
- Each band above 2,000 nSLOC holds only six or seven reports.
Estimated Cost by Size
This table assumes two auditors on EVM code, a standard timeline and no fix reviews. Each range uses the middle half of review lengths.
| nSLOC | Simple ($10K per auditor-week) | Typical ($20K per auditor-week) | Complex ($40K per auditor-week) |
|---|---|---|---|
| Up to 500 | $8K to $12K | $16K to $24K | $32K to $48K |
| 501 to 1,000 | $12K to $20K | $24K to $40K | $48K to $80K |
| 1,001 to 2,000 | $24K to $44K | $48K to $88K | $96K to $176K |
| 2,001 to 3,000 | $36K to $44K | $72K to $88K | $144K to $176K |
| 3,001 to 5,000 | $48K to $60K | $96K to $120K | $192K to $240K |
| Over 5,000 | $44K to $92K | $88K to $184K | $176K to $368K |
Above 5,000 nSLOC the spread is wide, so get a scoped quote.
Run your own numbers
Change any input and the range updates.
Estimated total: $53,000 to $108,000
An estimate from public data, not a Guardian quote.
- Working days: 6 to 11
- Auditor-weeks: 2.4 to 4.4
- Review: $48,000 to $88,000
- Fix reviews: $5,000 to $20,000
Premiums and Add-Ons
Sherlock publishes these estimates. It sells audits, so treat them as one vendor's view.
| Factor | Effect on cost |
|---|---|
| Solana programs in Rust | +25% to 40% over EVM |
| Move (Sui, Aptos) or Cairo (StarkNet) | +30% to 45% over EVM |
| ZK circuits | +80% to 120% over EVM |
| Urgent timeline | +20% to 40% |
| Each re-audit pass after fixes | $5,000 to $20,000 |
Fix reviews
Plan for at least one. 53 of the 67 Guardian reports above include a remediation round.
Fuzzing and invariant suites
We found no public per-audit price for a fuzzing suite. Ask whether it sits inside the quoted auditor-weeks or on top.
Guardian's smart contract audit builds an invariant suite around the protocol's safety properties as one of its three passes.
Contests
Sherlock says contest cost scales with its timeline guidelines, but its pricing reference gives no dollar figure.
Check It Against Real Prices
These are the most useful public price points for audits:
| Record | Sample | Price |
|---|---|---|
| Arbitrum Audit Program, June 2026 | 14 completed audits, 21,882 lines | $46,363 average; $45 a line |
| Same report, above 3,000 lines | Larger codebases in that sample | About $15 a line |
| Arbitrum Audit Program, August 2026 | 18 completed audits, 71,366 lines | $50,706 average; about $15 a line |
| Arbitrum Security Subsidy Fund, 2024 pilot | Quotes for 22 selected projects, six firms | $16,500 to $345,979; $140,134 average |
| Sherlock estimate | Simple ERC-20 token | $5,000 to $20,000 |
| Sherlock estimate | Mid-complexity DeFi protocol | $40,000 to $100,000 |
The August 2026 figures come from Arbitrum's Security Program proposal. Disclosure: Guardian is one of 13 approved auditors listed in the June 2026 report, and three projects chose Guardian in the 2024 pilot.
How our tables compare, by our arithmetic:
- Arbitrum's 18 audits averaged 3,965 lines and $50,706: our Simple column for that size.
- The first 14 averaged 1,563 lines and $46,363: between our Simple and Typical columns.
- The 2024 pilot's quotes averaged $140,134, but the report gives no code sizes.
So subsidized audits came in below our Typical column. Arbitrum does not define its lines of code, so the match is rough.
For retainers and named-firm prices, see what top auditors charge.
Get a Firm Quote
A firm quote starts from the code. Guardian's smart contract audit is scoped from your repository and commit.
Send the repository, the commit, the files in scope and your target date. Sherlock warns that scope often grows once integration dependencies are counted.
A smaller scope costs less. How to prepare for a smart contract audit covers writing less code and other habits for a cheaper review.
When quotes arrive, compare auditor-weeks, named reviewers, fix-review rounds and methods, not just the total.
What a Vanguard quote covers
A Vanguard audit includes more than this formula prices:
- Two independent teams on one scope, one of them powered by Helix, Guardian's AI auditor.
- An invariant fuzzing suite.
- A $100,000 Guardian-funded Defender contest for Critical findings.
- A hosted bug bounty with $50,000 in Critical matching.
- Half the package cost back as credits toward offchain assessments.
- Six months of update review, up to 2,500 onchain or 10,000 offchain SLOC.
Teams can also apply for Guardian's $1,000,000 in security audit grants.
Frequently Asked Questions
How much does a smart contract audit cost?
Public records show a wide spread. Arbitrum's 18 completed subsidized audits averaged $50,706. In its 2024 subsidy pilot, quotes for 22 selected projects ran from $16,500 to $345,979 and averaged $140,134. Size, complexity, language and timeline drive the difference.
How is a smart contract audit priced?
Mostly by engineer time: how many auditors a scope needs, for how many weeks, usually judged from nSLOC. Arbitrum's Audit Program proposal says it is not uncommon to pay $10,000 to $40,000 per auditor per week, depending on complexity.
How long does a smart contract audit take?
In Guardian's public reports, main reviews of 1,001 to 2,000 nSLOC took a median of 8 working days, and 3,001 to 5,000 nSLOC a median of 14. Fix reviews follow on their own dates.
Does Guardian publish audit prices?
No. Guardian scopes each audit from your repository and commit, then quotes it. This calculator uses public market records and Guardian's published review lengths, so treat it as a planning range, not a quote.
Sources
- Arbitrum forum: Arbitrum Audit Program proposal (Feb 6, 2025)
- Arbitrum forum: Arbitrum Audit Program Transparency Report #3 (Jun 10, 2026)
- Arbitrum forum: Arbitrum Security Program proposal (Aug 13, 2026)
- Arbitrum forum: Arbitrum Security Subsidy Fund Outcome Report (Feb 18, 2025)
- Sherlock: Smart Contract Audit Pricing, A Market Reference for 2026 (Feb 2026)
- Guardian: Public audit portfolio (data as of Nov 5, 2026)
- Guardian: Smart Contract Audit
- Guardian: Vanguard
- Guardian: What Top Auditors Charge: OpenZeppelin Audit Cost and More (Oct 2026)
Turn your estimate into a firm quote
Send Guardian your repository and commit, and compare a scoped Vanguard quote line by line with this range.