Build vs Buy Calculator
Building custom software costs 3 to 10 times more than buying an existing solution over 5 years according to Gartner research. Enter your requirements to compare total cost of ownership for build versus buy including development time, maintenance, and opportunity cost.
Last updated: May 2026
The build vs buy decision compares the total cost of developing software in-house against purchasing an existing solution. Build Total = Initial Development Cost + (Annual Maintenance × Years). Break-even (build vs buy) typically target Build cheaper within 2 years.
📊 Your visitors see this on your website. SaaS founders embed this tool on their website — visitors benchmark themselves against industry data and you capture every input as a qualified lead. See plans →
↑ This is exactly what your website visitors see when you embed this tool. The only difference: their results are gated behind an email capture form, and every input is sent to your CRM.
What is Build vs Buy Decision?
The build vs buy decision compares the total cost of developing software in-house against purchasing an existing solution. Building offers full customization and no recurring license fees, while buying provides faster deployment and proven reliability. The right choice depends on how core the functionality is to your competitive advantage. Compare SaaS investment returns with the SaaS ROI Calculator and evaluate vendors with the Vendor Comparison Calculator.
The Formula
Build Total = Initial Development Cost + (Annual Maintenance × Years) Buy Total = (Annual License Fee × Years) + Implementation Cost + Training
Worked Example
A company needs a project management tool. Build: $40,000 initial development + $8,000/year maintenance. Buy: $12,000/year license + $5,000 implementation. 5-year comparison.
- Build total = $40,000 + ($8,000 × 5) = $80,000
- Buy total = ($12,000 × 5) + $5,000 = $65,000
- Year 1: Build $48,000 vs Buy $17,000
- Break-even: Build becomes cheaper at year 8.75
📌 Over 5 years, buying saves $15,000 (19%). Building only becomes cheaper after year 8.75 — and that assumes zero scope changes or major refactoring.
Why This Matters
Opportunity cost
Developers building internal tools aren't building your product. If your engineering team is your biggest expense and competitive advantage, every hour spent on non-core tools is an hour not spent on features that drive revenue.
Maintenance burden
Custom software requires ongoing maintenance: bug fixes, security patches, infrastructure updates, and feature requests. This "maintenance tax" of 15-25% of initial build cost per year is often underestimated and grows as the codebase ages.
Common Mistakes
❌ Underestimating build costs by 2-3x
Software projects consistently overrun estimates. A $40,000 estimate typically becomes $80,000-120,000 once edge cases, testing, documentation, and scope changes are included. Always multiply initial estimates by 2-3x for realistic budgeting.
❌ Building commodity features
If the functionality exists in mature SaaS products (CRM, email, project management, analytics), buying is almost always better. Build only when the tool is core to your competitive advantage and no existing solution meets your needs.
Industry Benchmarks
| Category | Good | Average | Poor |
|---|---|---|---|
| Break-even (build vs buy) | Build cheaper within 2 years | 3-5 years | Build never cheaper |
| Maintenance as % of build cost | Below 15% | 15-25% | Above 30% |
Source: Flexera State of IT Report
Benchmark data sourced from Flexera State of IT Report.
From working with SaaS founders, the ones who embed a metrics calculator on their investor or pricing page consistently report shorter sales cycles — prospects arrive at the call already knowing their numbers.
One of the most common mistakes we see when working with clients: underestimating build costs by 2-3x. Software projects consistently overrun estimates. A $40,000 estimate typically becomes $80,000-120,000 once edge cases, testing, documentation, and scope changes are included. Always multiply initial estimates by 2-3x for realistic budgeting.
Embed This Calculator on Your Website
Every visitor who uses your embedded calculator becomes a qualified lead. Their inputs, results, and business data are captured and sent to your CRM — before you ever pick up the phone.
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Custom software projects take 4.5 times longer than estimated on average according to Standish Group data. Answer 5 questions about your requirements, timeline, team skills, and maintenance capacity to get a data driven recommendation on building versus buying with pros and cons.