CAC Payback & Cash Flow Simulator
Simulate how long new customer cohorts take to break even on acquisition costs based on order contribution margin and repurchase frequency.
Customer & Cohort Parameters
Model acquisition costs, basket size, unit contribution, and repeat order cycles.
Model Assumption: The simulation holds AOV and contribution margin constant between initial checkout and subsequent repeat purchases.
Estimated Payback Period
Full acquisition recovery occurs across repeat orders, requiring approximately 30 days to reach cash break-even.
Orders to Break Even
1.5×
Contribution: $40.00
Order 1 Cash Float
-$20.00
Per new customer
Acquiring 1,000 customers/mo at this rate requires floating $20,000 in working capital until repurchase cycles mature.
How the Math & Economics Work
Understand the exact equations, managerial accounting rules, and unit economics governing these metrics in modern e-commerce.
Payback Days ≈ (Orders to Payback − 1) × Days Between Repeat Purchases. This models how long an acquired customer takes to generate enough cumulative contribution profit to fully offset their initial acquisition cost.
Paid to ad networks upfront
Order 1 retail checkout
After COGS, shipping, gateway fees
$40 contribution − $60 ad spend
Occurs at Day 60 without repeat ad spend
Break-even occurs during the second purchase, turning cumulative contribution cash positive (+$20).
The Working Capital Expansion Trap
This simulation holds AOV and unit variable costs constant across purchase cycles. In practice, the primary operational risk of a non-immediate payback period is cash-flow compression: if a merchant scales paid spend aggressively with a 60-day payback, they must float inventory and ad invoices out of existing reserves until retention orders materialize.
Frequently Asked Questions
Track True Cash Return with Margain
Pair your Meta ad spend directly with confirmed Shopify orders and order-level contribution margins using Margain Financial Clarity.
Related Guides & Playbooks
Deep-dive operational frameworks explaining the unit economics, cash cycles, and marketing attribution behind this calculator.
Cash vs. Accrual Accounting: Why Your Shopify Dashboard and Bank Never Agree
Stop the confusion between daily store cash flow and monthly accountant P&Ls. Learn how cash, accrual, and contribution margin reconcile e-commerce profits.
CAC Payback Period: The Cash Flow Metric E-Commerce Operators Ignore
Learn how to calculate CAC payback period in e-commerce, why high LTV brands still run out of cash, and how to model order cycles against working capital.
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