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SaaS Unit Economics Template

Key Metrics​

Customer Acquisition Cost (CAC)​

Formula: Total Sales & Marketing Spend / New Customers Acquired

Example calculation:

Monthly marketing: $5,000
New customers: 50
CAC = $5,000 / 50 = $100

Benchmarks by channel:

  • Organic (SEO, content): $50-200
  • Paid ads (Google, Facebook): $100-500
  • Sales-led: $500-5,000+
  • Viral/referral: $10-50

What's good: CAC < 1/3 of LTV (Rule of thumb: LTV:CAC ratio of 3:1 or higher)

Lifetime Value (LTV)​

Formula: ARPU × Gross Margin % / Churn Rate

Example calculation:

ARPU (Average Revenue Per User): $20/month
Gross Margin: 80%
Monthly Churn: 5%

LTV = ($20 × 0.80) / 0.05 = $320

Alternative (simple): ARPU × Average Customer Lifespan

ARPU: $20/month
Average lifespan: 16 months (1 / 0.05 monthly churn)
LTV = $20 × 16 = $320

Benchmarks:

  • B2C SaaS: $100-500
  • SMB SaaS: $500-5,000
  • Enterprise SaaS: $10,000-100,000+

Churn Rate​

Monthly Churn Formula: Customers Lost This Month / Customers at Start of Month

Example:

Start of month: 100 customers
Lost: 5 customers
Monthly churn = 5 / 100 = 5%

Annual churn: 1 - (1 - Monthly Churn)^12

Monthly churn: 5%
Annual churn = 1 - (0.95)^12 = 46%

Benchmarks:

  • Excellent: <3% monthly (<30% annual)
  • Good: 3-5% monthly (30-46% annual)
  • Average: 5-7% monthly (46-58% annual)
  • Poor: >7% monthly (>58% annual)

Churn causes:

  • Bad onboarding (30-40% churn in first 90 days)
  • Lack of value delivery
  • Poor product-market fit
  • Price sensitivity
  • Competitor switches

Payback Period​

Formula: CAC / (ARPU × Gross Margin %)

Example:

CAC: $100
ARPU: $20/month
Gross Margin: 80%

Payback = $100 / ($20 × 0.80) = 6.25 months

Benchmarks:

  • Excellent: <6 months
  • Good: 6-12 months
  • Acceptable: 12-18 months
  • Poor: >18 months

Why it matters: Cash flow - Shorter payback = faster reinvestment in growth

Monthly Recurring Revenue (MRR)​

Formula: Total Paying Customers × ARPU

Example:

Customers: 500
ARPU: $20
MRR = 500 × $20 = $10,000

MRR Growth Rate: (This Month MRR - Last Month MRR) / Last Month MRR

Last month: $10,000
This month: $11,000
Growth = ($11,000 - $10,000) / $10,000 = 10%

Components:

  • New MRR (new customers)
  • Expansion MRR (upgrades)
  • Contraction MRR (downgrades)
  • Churned MRR (cancellations)

Annual Recurring Revenue (ARR)​

Formula: MRR × 12

Example:

MRR: $10,000
ARR = $10,000 × 12 = $120,000

Valuation multiples (rough):

  • Early stage ($0-1M ARR): 5-10x ARR
  • Growth stage ($1-10M ARR): 10-20x ARR
  • Late stage ($10M+ ARR): 5-15x ARR (depends on growth rate)

Gross Margin​

Formula: (Revenue - Cost of Goods Sold) / Revenue

For SaaS:

Revenue: $20,000/month
COGS (hosting, support, payment fees): $4,000/month
Gross Margin = ($20,000 - $4,000) / $20,000 = 80%

SaaS COGS typically includes:

  • Cloud hosting (AWS, GCP, Azure)
  • Payment processing fees (2-3%)
  • Customer support labor
  • Data storage
  • Third-party API costs

Benchmarks:

  • Excellent: 80-90%
  • Good: 70-80%
  • Average: 60-70%
  • Poor: <60%

Complete Unit Economics Example​

Example SaaS Product: API Testing Tool

Pricing: $15/month

Metrics:

  • ARPU: $15/month
  • Monthly Churn: 4%
  • CAC (organic): $75
  • Gross Margin: 85%

Calculations:

  1. LTV:
LTV = ($15 × 0.85) / 0.04 = $318.75
  1. LTV:CAC Ratio:
$318.75 / $75 = 4.25:1 (Excellent! >3:1)
  1. Payback Period:
$75 / ($15 × 0.85) = 5.9 months (Excellent! <6 months)
  1. Average Customer Lifespan:
1 / 0.04 = 25 months
  1. Monthly MRR (with 500 customers):
500 × $15 = $7,500
  1. Annual ARR:
$7,500 × 12 = $90,000

Assessment: Healthy unit economics. LTV:CAC ratio of 4.25:1 and payback period of 6 months indicates sustainable growth potential.

Growth Scenarios​

Scenario 1: Bootstrapped Growth (Conservative)​

Assumptions:

  • Start: $0 ARR
  • Monthly growth: 10% (organic)
  • CAC: $50 (SEO, content)
  • Churn: 4%

Year 1: 10K→10K → 120K ARR Year 2: 120K→120K → 400K ARR Year 3: 400K→400K → 1M ARR

Scenario 2: Funded Growth (Aggressive)​

Assumptions:

  • Start: $0 ARR
  • Monthly growth: 20% (paid ads)
  • CAC: $150 (paid + sales)
  • Churn: 5%

Year 1: 10K→10K → 300K ARR Year 2: 300K→300K → 2M ARR Year 3: 2M→2M → 10M ARR

Burn rate: Higher CAC, lower profitability, faster growth

Red Flags​

Unsustainable economics:

  • LTV:CAC <2:1 (burning money on acquisition)
  • Payback period >18 months (cash flow problem)
  • Churn >7% monthly (product-market fit issue)
  • Gross margin <60% (cost structure problem)
  • Negative cohort economics (later cohorts worse than earlier)

Warning signs:

  • Growing ARR but shrinking margin
  • Decreasing ARPU over time
  • Increasing churn over time
  • CAC increasing faster than LTV

Optimization Levers​

Increase LTV​

  1. Reduce churn:

    • Better onboarding
    • Proactive customer success
    • Usage monitoring (prevent silent churn)

  2. Increase ARPU:

    • Upsells (higher tiers)
    • Cross-sells (add-ons)
    • Annual plans (pay upfront discount)

  3. Expand accounts:

    • Per-seat pricing (team growth)
    • Usage-based pricing (customer grows, revenue grows)

Decrease CAC​

  1. Improve conversion:

    • Better landing pages
    • Free trial optimization
    • Onboarding improvements

  2. Cheaper channels:

    • Content marketing (SEO)
    • Referrals (viral loops)
    • Word-of-mouth (product-led growth)

  3. Increase efficiency:

    • Marketing automation
    • Self-serve signup
    • Bottom-up adoption

Tools & Resources​

Calculate metrics:

Benchmarks:

Reading: