Find out how long it takes for a newly acquired client to pay back your customer acquisition cost (CAC) — based on contribution margin, recurring revenue, and retention, not just gross revenue.
Enter values — results update live
Include ads, lead generation cost, sales calls, proposals, and onboarding time.
Percentage of revenue left after direct delivery costs (contractors, software, materials).
Leave at 0 if the client is purely project-based.
Leave blank to auto-calculate from margin and recurring revenue.
Contribution-based, not revenue-based
Estimated payback period
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How long until CAC is recovered
Monthly contribution
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Break-even month
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Revenue before payback
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Profit after CAC
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Estimated client lifetime value (LTV)
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Contribution over full retention period
LTV : CAC ratio
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Payback is based on contribution (revenue minus direct delivery costs), not gross revenue. A client can look profitable on revenue yet still take a long time to repay CAC if margins are thin.
CAC
Total cost to acquire one client — ads, lead generation, sales time, onboarding.
Contribution
Revenue minus direct delivery costs. This is what actually repays CAC.
Payback period
Months of contribution needed to fully recover the acquisition cost.
LTV
Total contribution over the client's full retention period.
The client acquisition payback period is the number of months it takes for the contribution margin from a newly acquired client to equal the client acquisition cost (CAC). This is a more realistic view than looking at gross revenue, because a large project fee can still be unprofitable after delivery costs.
For example, a project with $2,500 revenue but only 40% contribution margin generates $1,000 of contribution. If CAC is $600, it takes less than one project to break even. But if CAC is $3,000, it may take several projects or months of recurring revenue to recover the cost. That is why payback depends on contribution, not revenue alone.
1. Identify CAC
Add up all sales and marketing costs to acquire one client.
2. Find contribution
Subtract direct delivery costs from revenue to get contribution margin.
3. Divide and track
CAC ÷ monthly contribution = payback period in months.
Important: There is no universally “good” or “bad” payback period. Acceptable payback depends on your margins, cash flow, retention, and business model. A short payback preserves cash; a longer payback may be fine if lifetime value is high and retention is strong.
See how different models change the payback period.
CAC $400 · Project $1,500 · Margin 70% · No recurring
Contribution$1,050
Payback0.4 months
LTV$1,050
CAC $2,000 · Retainer $2,500/mo · Margin 45% · Retention 12 months
Monthly contribution$1,125
Payback1.8 months
LTV (12 mo)$13,500
CAC $5,000 · Setup $3,000 · Recurring $1,200/mo · Margin 80%
Monthly contribution$960
Upfront contribution$2,400
Payback2.7 months
Client acquisition payback is the time it takes for the contribution margin from a new client to equal the cost of acquiring that client (CAC). It tells you how many months of profit are needed before the acquisition investment is recovered.
Gross revenue includes money that must be spent on delivery — contractors, software, materials, and support. Only the contribution margin (revenue minus those direct costs) is actually available to repay CAC. Using revenue alone can make payback look faster than it really is.
Add all costs directly tied to acquiring clients over a period — ads, lead generation tools, networking, sales calls, proposal writing, and onboarding — then divide by the number of new clients won in that period. This gives your average CAC.
Set recurring monthly revenue to 0. The calculator will use the upfront project contribution to determine payback. If CAC is larger than the project contribution, payback will extend into future projects or additional work from the same client.
Not necessarily. A short payback preserves cash flow, which is helpful, but a longer payback can still be acceptable if the client's lifetime value is high and retention is strong. The right payback depends on your margins, cash reserves, and business model.
The retention period limits how much recurring contribution you can collect from a client. If payback requires more months than the client stays, you may never fully recover CAC through that client alone. Retention directly affects client lifetime value (LTV) and the LTV:CAC ratio.
There is no universal rule. Many businesses look for an LTV:CAC ratio of at least 3:1, but this depends on margins, growth stage, and cash flow. A lower ratio may be acceptable in high-retention models, while a higher ratio is safer when revenue is unpredictable.
Yes. The calculator works for freelancers, agencies, consultants, and any service business. Enter your total client acquisition cost — including lead generation cost, sales commissions, and marketing spend — to estimate payback based on contribution.
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