We Built a Free AI ROI Calculator — Here's the Data Behind It
The premise: Every startup considering AI agents asks "what's the ROI?" — but nobody gives them a calculator. We built one. Then we sent it to 10 YC companies. Here's what happened.
## The Problem: AI Agent Economics Are Opaque
You're a founder. You're thinking about adding AI agents to your stack. You know it could save time, but you can't answer the basic question:
"If I spend $500/month on AI agents, what do I actually get back?"
The industry is full of hype. "AI will 10x your team!" But nobody shows the math. No calculator. No framework. Just vibes.
So we built one.
## The Calculator: What It Measures
The AI Agent ROI Calculator takes 6 inputs:
| Input | What It Captures |
|-------|-----------------|
| Team size | How many people could be augmented |
| Avg hourly cost | Fully-loaded cost per engineer/PM/marketer |
| Hours saved per week | Per person, from AI automation |
| AI tool monthly cost | API fees + subscriptions |
| Implementation hours | One-time setup cost |
| Expected accuracy rate | AI output quality (70-95%) |
And it outputs:
| Output | Why It Matters |
|--------|---------------|
| Monthly net savings | The real number after costs |
| Annual ROI % | For the CFO conversation |
| Payback period | How fast the investment breaks even |
| Hours recovered per month | For capacity planning |
## The Math Behind It
Here's the core formula:
def calculate_roi(team_size, hourly_cost, hours_saved_weekly,
monthly_ai_cost, impl_hours, accuracy_rate):
"""
AI Agent ROI Calculator — Core Formula
"""
# Effective hours saved (adjusted for AI accuracy)
effective_hours = hours_saved_weekly * (accuracy_rate / 100)
# Monthly value of time saved
monthly_value = effective_hours * hourly_cost * 4.33 # weeks per month
# Implementation cost (amortized over 12 months)
impl_monthly = (impl_hours * hourly_cost) / 12
# Net monthly savings
net_monthly = monthly_value - monthly_ai_cost - impl_monthly
# Annual ROI
annual_savings = net_monthly * 12
annual_cost = monthly_ai_cost * 12 + impl_hours * hourly_cost
roi_percent = ((annual_savings - annual_cost) / annual_cost) * 100
# Payback period (months)
if net_monthly > 0:
payback = (impl_hours * hourly_cost) / net_monthly
else:
payback = float('inf')
return {
"monthly_net_savings": round(net_monthly, 2),
"annual_roi_percent": round(roi_percent, 1),
"payback_months": round(payback, 1),
"hours_recovered_monthly": round(effective_hours * 4.33, 1)
}
# Example: 5-person startup, $80/hr, 10 hrs/week saved, $300/mo AI cost
result = calculate_roi(
team_size=5,
hourly_cost=80,
hours_saved_weekly=10,
monthly_ai_cost=300,
impl_hours=20,
accuracy_rate=85
)
print(f"Monthly net savings: ${result['monthly_net_savings']:,.0f}")
print(f"Annual ROI: {result['annual_roi_percent']}%")
print(f"Payback period: {result['payback_months']} months")
print(f"Hours recovered/month: {result['hours_recovered_monthly']}")