Build vs Buy Calculator | Make Data-Driven Decisions

Build Costs

Engineer-Months Required

How many months of engineering time to build?

Monthly Engineer Cost (Fully Loaded)

Salary + benefits + overhead

Monthly Maintenance Hours (optional)

Ongoing support, updates, bug fixes

Hourly Rate (optional)

(Revenue Impact) (optional)

Lost revenue from delayed features

Hidden Costs (Infrastructure, Security, etc) (optional)

Buy Costs

💡 Time to Value: The time from "we decided to do this" until "it's working and people are using it." For building, this includes development, testing, and bugs. For buying, this includes setup, integration, and team onboarding.

Annual SaaS Cost

Yearly subscription cost

Implementation Cost (optional)

One-time setup, integration, training

Time to Value: Build (months)

How long until your team finishes building and it's actually usable in production? Include testing, bugs, iterations.

Time to Value: Buy (weeks)

How long until the SaaS is set up, integrated, and your team is actually using it? Include onboarding, training, API integration.

⚠️ Reality Check: Advanced Factors (Show)

Real talk: Most calculators assume everything goes perfectly. This one doesn't. Add these factors for a realistic view.

Build Reality Check

Probability Build Runs Over Budget (%) (optional)

Industry average: 70% of projects run over. Be honest.

Cost Overrun if Delayed (optional)

Extra cost if build takes longer than planned

(Engineer Quits) (optional)

Cost to hire + train replacement + document their code

Support Hours/Month (User Questions) (optional)

Separate from maintenance. Slack pings, bug reports, onboarding.

Annual (optional)

SOC 2, GDPR, security audits, pen testing (yearly)

Cost to Scale at 10x Users (optional)

Infrastructure + optimization when usage explodes

(%) (optional)

How much slower is the team while 1 person builds this?

Additional Costs

Need to Hire Someone? (optional)

Recruiter fee ($20K) + 3-5 months delay

(months) (optional)

How long are you behind competitors who bought SaaS?

of Being Behind (optional)

Lost deals, slower growth, customer churn per month you're behind. Multiply Competitive Delay × This = Total Cost.

(Switch Later) (optional)

Cost to migrate away if your build sucks

(Vendor Lock-in) (optional)

Cost to export data and switch vendors

: Build (%) (optional)

What % of needed features will v1 actually have?

Hours/Month (optional)

When things break, feature requests pile up, etc.

(months) (optional)

When everything goes wrong (scope creep, bugs, etc.)

Results

Build: Year 1 Total

Buy: Year 1 Total

3-Year TCOTotal Cost of Ownership = ALL costs over 3 years, not just the sticker price. Includes maintenance, support, compliance, opportunity cost, etc. (Total Cost of Ownership)

What you'll actually spend over 3 years when you add up everything

Build (3 years) $0

Buy (3 years) $0

Difference $0

Cost Visualization

Year 1

Build

Buy

3 Years

Build

Buy

Recommendation: Calculate to see recommendation

Enter your costs above and click Calculate to get a recommendation.

Real-World Examples: What Building Actually Costs

❌ Example 1: Custom Testing Framework

"We'll build our own Selenium/Cypress - how hard can it be?"

BUILD Costs:

Initial: 12 engineer-months × $15K = $180K
Year 1 maintenance: $60K (browser updates, bugs)
Support burden: $36K (teaching everyone how to use it)
Compliance/Security: $20K (CI/CD integration, reporting)
Year 3 scale issues: $80K (parallelization, flaky tests)

3-Year Total: $456K

BUY Costs:

Playwright/Cypress: Free + open source
GitHub Actions CI: $5K/year
Browserstack (optional): $12K/year

3-Year Total: $51K

What Actually Happened:

Company built custom framework. 8 months in, Chrome updated and broke everything. Senior engineer who built it quit. New hire spent 3 months trying to understand the codebase. Eventually abandoned it and switched to Playwright.

Meanwhile: Competitors using Playwright shipped 12 product features in those 14 months. This company shipped 4 (QA team was blocked waiting for the tool).

Wasted: $240K + 14 months + lost market velocity

❌ Example 2: Internal CRM

"Sales wants one small feature Salesforce doesn't have - let's build our own!"

BUILD Costs:

Initial: 24 engineer-months × $15K = $360K
Year 1 maintenance: $120K (endless feature requests)
Support: $60K (sales rep questions 24/7)
Integrations: $80K (email, calendar, Slack, etc.)
Mobile app: $100K (sales wants it on iPhone)
Compliance: $40K (GDPR, data retention)

3-Year Total: $880K

BUY Costs:

HubSpot Professional: 10 seats × $500/mo = $60K/year
Custom workflow automation: $5K setup
Training: $3K (once)

3-Year Total: $188K

What Actually Happened:

Built MVP in 10 months. Sales used it for 3 months. Then: "Can we add mobile?" "Can we integrate with our email?" "Can we get reporting like Salesforce has?" Feature requests never stopped. After 18 months, switched to HubSpot. Sales team celebrated.

Team Impact: Pulled 2 senior engineers off product features for 10 months. Didn't hire more (budget constraints). Product roadmap delayed 2 quarters.

Market Impact: Competitor shipped AI features + mobile app while this team built a CRM. Lost 3 enterprise deals to competitor's "more modern platform."

Wasted: $480K + 18 months + 3 lost deals ($450K ARR) + market positioning

❌ Example 3: AI Sales SDR Tool

"AI makes this easy - we'll build our own Outreach/Apollo!"

BUILD Costs:

Initial: 18 engineer-months × $15K = $270K
Data vendor: $60K/year (ZoomInfo/Apollo access)
AI API costs: $40K/year (Claude/GPT-4 at scale)
Email infrastructure: $30K/year (deliverability, IPs)
Compliance lawyer: $25K (CAN-SPAM, GDPR)
Maintenance: $80K/year (email warmup, deliverability tuning)

3-Year Total: $900K

BUY Costs:

Apollo.io: $15K/year (data + automation)
Clay: $8K/year (AI enrichment)
Instantly.ai: $6K/year (email warmup)
Setup/training: $5K (once)

3-Year Total: $92K

What Actually Happened:

Built AI SDR tool using GPT-4. Worked great in testing. Production launch: emails went to spam. Spent 4 months fixing deliverability. Data quality issues. Unsubscribe handling broken. Compliance risks. Legal got involved. Project paused "temporarily" after 14 months. Now using Apollo + Clay.

Team Burn: Only had 6 engineers total. 2 worked on this (33% of eng capacity). Couldn't hire more fast enough. Product velocity dropped 40%. Eng team burnout from context switching.

Market Reality: While building this, 3 competitors launched with Apollo + Clay in 2 weeks. Their SDRs were already booking meetings. This company's SDRs? Still waiting for the "tool" to be ready.

Wasted: $470K + 14 months + team burnout + 14 months of competitive disadvantage

The Pattern

The Question You're Not Asking:

Do you have spare engineering capacity?

If YES: You can hire more engineers → Maybe building makes sense (but are you hiring fast enough?)
If NO: You're pulling engineers OFF product features → Competitors ship faster → You lose market share

While you build an internal tool for 12 months, your competitor using SaaS ships 20 product features. Who wins the market?

Why "Build" Always Costs More

Team capacity drain - Engineers pulled off product
Competitive disadvantage - Rivals ship faster
Market share loss - Behind on features that matter
You underestimate maintenance (it compounds)
Feature creep is inevitable
People quit, knowledge leaves
Third-party integrations are a nightmare
Compliance catches you off guard
Every browser/OS update breaks something
Support burden falls on engineering

Why "Buy" Actually Wins

No team capacity burned - Engineers stay on product
Market velocity maintained - Ship features competitors don't have
Competitive parity in 2 weeks - Not 14 months
SaaS vendors eat maintenance costs
Features ship without your team building them
Integrations already exist
Compliance is their problem
Support is their job, not yours
You can switch vendors if it sucks

Average savings by buying instead of building:

$405,000 per tool

Based on 3-year TCOTotal Cost of Ownership = everything you'll spend over 3 years (not just initial cost) across the examples above

+ Lost market opportunities from 12-18 months of slower product velocity

But Wait — When SHOULD You Build?

Not everything should be bought. Here's when building actually makes sense:

✓ Stripe built their own fraud detection

At their scale, buying fraud tools would cost 10x more. Plus, it's their competitive advantage.

✓ Netflix built their own CDN

Serving billions of video streams. No CDN vendor could handle their scale at reasonable cost.

✓ Airbnb built their own payment processing

Complex escrow flows between hosts and guests. No SaaS handled their specific use case.

✓ Trading firms build their own execution engines

Milliseconds matter. Their core product. Can't buy competitive advantage.

✓ xAI bought processors for Grok instead of renting cloud

Training LLMs at scale. Renting GPUs from AWS/Azure would cost 5x more long-term. Owning the hardware makes sense.

The Pattern: When Building Wins

This IS your product (not a support tool)
Buying would cost 5-10x more at your scale
No SaaS exists for your specific need
It's your competitive advantage
You have the capacity (not pulling engineers off revenue features)

But a sales CRM? An analytics dashboard? An email tool? That's not your competitive advantage. That's you trying to be HubSpot.

The Hidden Cost Nobody Tracks

You spend $500K building an internal tool over 14 months.

Your competitor spends $50K on SaaS, deploys in 2 weeks.

They use those 14 months to ship features you don't have.

They win deals. You're still "working on it."

The real cost isn't the $500K. It's the market share you lost while building a tool that already existed.