Due Diligence Cost Calculator
Estimate what a deal’s due diligence will cost — by workstream, not as a single mystery number. Pick a deal type and size, check the workstreams you need, and every range is quoted straight from our published, sourced cost guides. It shows ranges, never sales quotes, and it tells you where a number does not exist rather than inventing one.
| Workstream | Cost range | Source |
|---|---|---|
| Financial / Quality of Earnings (QoE) | $25k–$60k | per Due Diligence Costs (2026) |
| Legal | $15k–$50k | per Due Diligence Costs (2026) |
| Tax | $20k–$50k | per Due Diligence Costs (2026) |
| Technology / ITFew days pre-LOI, 2–4 weeks post-LOI, confirmatory pass before close | $10k–$25k | per Due Diligence Costs (2026) |
| Cybersecurity | $5k–$15k | per Due Diligence Costs (2026) |
| Estimated total | $75,000–$200,000 |
Sanity check: our published deal-size ladder puts a mid-market — $10m to $100m deal at $50k–$200k all-in across all workstreams. If your selected total lands far outside that, you are either over- or under-scoping. Timeline: 6–8 weeks for a full-scope process.
Data room cost for this deal profile
derived from the published $52/admin/mo flat rate- Flat per-admin$312 for 6 months, $624/year. A 3-month slip adds exactly $156 — not an extension invoice.
- Legacy per-pagea ~10,000-page room at $0.40–$0.85 per page is $4,000–$8,500 in upload fees alone.
- Overrun riskSRS Acquiom found actual VDR costs exceed initial quotes by 2–10x across 3,800+ M&A deals. per Virtual Data Room Cost Guide
Every figure is a published range, not a quote, and is computed in your browser from a constants block — nothing you enter is sent to or stored on our servers. Ranges, not quotes: your actual bill depends on complexity, data quality, and timeline.
How are these due diligence cost estimates calculated?
Every range in this calculator is lifted verbatim from a published Peony cost guide — nothing here is a live sales quote or a made-up figure. When you check a workstream, the tool sums the low and high ends of that workstream’s published range for the deal size you selected. The M&A workstream numbers (QoE, legal, tax, technology, cybersecurity, commercial) come from the deal-size cost summary in our due diligence cost breakdown. The commercial real estate report costs — Phase I ESA, ALTA/NSPS survey, Property Condition Assessment, MAI appraisal — come from our commercial property due diligence guide.
Where our published writing declines to give a number, so does the calculator. Insurance diligence is the clearest case: our insurance due diligence guide explains that the figure varies too widely by program to publish a single reliable number, so the tool shows “varies” for that line instead of inventing precision.
What does due diligence actually cost in 2026?
For an M&A company acquisition, total external due diligence typically runs 0.2%–4% of deal value. In absolute dollars that is roughly $25k–$75k for deals under $10M, $50k–$200k for $10M–$100M deals, and $150k–$500k+ above $100M. Financial (QoE) and legal are the two largest line items in every band — a QoE alone ranges from about $10k–$30k on a clean single-entity business to $60k–$100k+ on a larger multi-entity target. A full-scope process usually takes 6–8 weeks.
Commercial real estate is priced per report rather than by deal size: a Phase I ESA runs $2,000–$5,000, an ALTA/NSPS survey $3,000–$8,000, a Property Condition Assessment $1,500–$10,000, and an MAI appraisal $4,000–$10,000 — roughly $12,000–$30,000 all-in before any Phase II, over a 30–90 day window. A fundraise carries no third-party diligence bill on the founder’s side at all; the only cost you control there is the data room you present.
Why do due diligence quotes overrun?
Because the number you are quoted rarely includes the fees that actually accrue. On the adviser side, scope creep and messy data drive extra rounds — I have watched a QoE budgeted at $30k land at $45k because the target’s revenue recognition needed three rounds of follow-up. On the data room side, the gap is even starker: SRS Acquiom found actual VDR costs exceed initial quotes by 2–10x across 3,800+ M&A deals — driven by per-page upload fees ($0.40–$0.85/page), storage overages ($75–$300/GB), setup fees, extra-user charges, and deal-extension fees when the timeline slips. One documented case saw a ~$3,800 quote balloon to $38,168.
The single most controllable lever is data quality. A clean, well-organized room cuts adviser time — and cost — 25–35% by avoiding redundant work and clarifying scope up front. That is the whole reason a calculator like this shows ranges, not quotes: the low end of every range is what you pay when you show up organized, and the high end is what you pay when the advisers have to untangle the mess first.
When should you not trust a due diligence cost calculator?
Any calculator — this one included — gives you a planning range, not a firm number, and it is worth being honest about the limits. It cannot price your specific target, whose complexity, number of jurisdictions, data quality, and timeline can move the real figure by tens of thousands of dollars. It cannot know that your target has four years of deferred revenue to untangle, or a cross-border structure that adds a workstream. And it should never dress up a number it does not have: when a workstream has no reliable published range, the honest output is “varies — see the guide,” not a fabricated figure. Use the output to budget and to catch obvious over- or under-scoping, then get real quotes from the advisers who will actually do the work.
What should the data room itself cost?
The data room is the small, controllable line item — and the one that most reduces the large one. The calculator shows two models side by side for your deal profile because the model matters more than the provider. Flat per-admin pricing gives you a number you can predict: legacy per-page pricing does not. On a 10,000-page deal, per-page fees alone run $4,000–$8,500 before storage or user charges — and then the overruns start.
I run Peony, a data room company, and this is how the numbers land for our 6,800+ customers. The free tier ($0) covers a first diligence folder or a lean seed raise with enterprise-grade encryption, audit trails, and page-level analytics. Business is $30 per admin per month with screenshot protection, NDA gates, and basic AI document Q&A. Data Room is $52 per admin per month with dynamic per-viewer watermarks and unlimited rooms — which is $312 for a six-month deal, and if the deal slips three months the cost rises by exactly $156, a derived figure from the flat monthly rate rather than an extension invoice. Viewers are always unlimited and free. Compare that to legacy platforms quoting five figures for the same deal, and the data-room line stops being where your budget leaks.
Due diligence cost calculator FAQ
How are these due diligence cost estimates calculated?
Every range in the calculator is quoted verbatim from a published Peony cost guide — not generated, not a live sales quote. M&A workstream ranges (QoE, legal, tax, technology, cybersecurity, commercial) come from the deal-size cost summary in our due diligence cost breakdown. Commercial real estate report costs (Phase I ESA, ALTA/NSPS survey, Property Condition Assessment, MAI appraisal) come from our commercial property due diligence guide. The data room lines are derived from Peony's published $52-per-admin-per-month flat rate and the legacy $0.40–$0.85 per-page range. When you check workstreams, the tool sums the low and high ends of each published range; it does not invent a total.
What does due diligence actually cost in 2026?
Across M&A deals, total external due diligence runs about 0.2%–4% of deal value. In absolute dollars that is roughly $25k–$75k for deals under $10M, $50k–$200k for $10M–$100M deals, and $150k–$500k+ above $100M. Financial (QoE) and legal are the two largest line items in every size band. Commercial real estate is priced differently — buyer-funded third-party reports run roughly $12,000–$30,000 all-in before a Phase II. These are ranges; the exact figure turns on deal complexity, number of workstreams, provider type, timeline pressure, and how organized the data is.
Why do due diligence and data room quotes overrun?
Because the initial quote rarely includes the fees that actually accrue. On the diligence side, scope creep and messy data drive extra adviser rounds — a QoE budgeted at $30k can land at $45k when revenue recognition is a mess. On the data room side, SRS Acquiom found actual VDR costs exceed initial quotes by 2–10x across 3,800+ M&A deals, driven by per-page upload fees ($0.40–$0.85/page), storage overages ($75–$300/GB), setup fees, additional-user charges, and deal-extension fees when the timeline slips. One documented case saw a ~$3,800 quote balloon to $38,168. The single most controllable lever is data quality: a clean, well-organized room cuts adviser time 25–35%.
Should I trust a due diligence cost calculator?
Trust it as a planning range, not a firm number. A calculator can tell you the shape of the bill and whether you are over- or under-scoping — it cannot price your specific target, whose complexity, jurisdiction count, data quality, and timeline move the real figure by tens of thousands of dollars. Treat the output the way we frame it: honest published ranges to budget against, not a quote to sign. When a workstream has no reliable published range — insurance diligence is the clearest example, where cost varies too widely by program to publish a single number — this tool says 'varies' rather than inventing precision.
What is the difference between the diligence cost and the data room cost?
They are two separate bills. The diligence cost is what you pay outside advisers — accountants for the QoE, lawyers for legal review, engineers for technical diligence, environmental firms for a Phase I. The data room cost is the software you use to run the process — the secure room where documents are shared, gated, watermarked, and tracked. The diligence bill is the large, variable one (tens of thousands of dollars). The data room bill is the small, controllable one, and it is the single lever that most reduces the diligence bill by cutting redundant adviser work.
How much should the data room itself cost for my deal?
Far less than most teams assume, and it should be a fixed number you can predict. On Peony, the free tier ($0) covers a first diligence folder or a lean seed-round raise with enterprise-grade encryption, audit trails, and page-level analytics. Business is $30 per admin per month, adding screenshot protection, NDA gates, and basic AI document Q&A. Data Room is $52 per admin per month, adding dynamic per-viewer watermarks and unlimited rooms — which works out to $312 for a six-month deal, and if the deal slips three months the cost rises by exactly $156 rather than an extension invoice. Viewers are always unlimited and free, so bidders, brokers, and their analysts add nothing to the bill. That is why 6,800+ customers run diligence on Peony instead of legacy per-page platforms that quote five figures for the same deal.
Where do the numbers behind this calculator come from?
From Peony's own published, sourced writing and first-party research. The workstream ranges live in our due diligence cost breakdown and commercial property due diligence guides; the data room math comes from our virtual data room cost guide; the overrun statistic is SRS Acquiom's analysis of 3,800+ M&A deals. The benchmark figures behind our platform stats — including that time-to-close reached about 8.6 months across 334 real M&A transactions in Q2 2026 — are indexed on Peony Research. Nothing you enter into the calculator is sent to or stored on our servers.