Lead Gen Budget Calculator (CAC Targets & Cost Per Lead)
Start from the number of new customers you want next month and work backwards: how many leads that takes at your conversion rate, what the monthly budget comes to at your cost per lead, and — the number that decides everything — whether the CAC that plan implies fits inside your LTV target. If it doesn't, the calculator shows the exact fix: the cost per lead you'd need to hit, or the conversion rate that would make your current cost per lead work.
Required monthly budget
$16,000.00
400 leads/mo at $40.00 per lead for 20 new customers
Leads needed / mo
400
Max affordable CPL
$40.00
Within target — plan is affordable
$800.00implied CAC vs$800.00target
Headroom of $0.00 per customer at your 3:1 LTV:CAC target — exactly on the line.
Implied vs target CAC
Funnel math
| Line | Value |
|---|---|
| Leads needed (20 ÷ 5%) | 400 |
| Required budget (leads × CPL) | $16,000.00 |
| Implied CAC (CPL ÷ rate ≡ budget ÷ goal) | $800.00 |
| Target CAC (LTV ÷ 3) | $800.00 |
| Max affordable CPL (target CAC × rate) | $40.00 |
| Headroom per customer | $0.00 |
Compare scenarios
Run the same calculation with two or three input sets side by side. Differences are highlighted; every number comes from the same tested formula as the calculator above.
| Input | Scenario A | Scenario B |
|---|---|---|
| New Customers Goal | ||
| Lead To Customer Rate | ||
| Avg Customer Ltv | ||
| Target Ltv Cac Ratio | ||
| Blended Cost Per Lead |
How it works
Leads needed is your customer goal divided by your lead-to-customer conversion rate: 20 customers at a 5% rate means 400 leads. Multiply by your blended cost per lead and you have the required monthly budget. These two numbers are pure arithmetic on your own funnel data — the calculator adds no assumptions, benchmarks, or industry averages of its own.
Implied CAC is what the plan actually pays per customer. It can be computed two ways that must agree: cost per lead divided by conversion rate, or total budget divided by the customer goal — both give the same answer, which is a useful sanity check that the plan hangs together. Target CAC comes from the other direction: customer lifetime value divided by your target LTV:CAC ratio, i.e. the most a customer is worth paying for.
The verdict is the headroom between the two: target CAC minus implied CAC. Zero or positive means the plan is affordable at your target. Negative means the plan overpays per customer, and there are exactly two levers: pay less per lead (the calculator shows your maximum affordable cost per lead) or convert more of the leads you already buy (it shows the conversion rate that would make your current cost per lead affordable — and tells you when no conversion rate can, because the lead itself costs more than the target CAC).
Frequently asked questions
What conversion rate should I use?+
Your own funnel's trailing three-to-six-month lead-to-customer rate is the only number worth trusting — pull it from your CRM, not from a published benchmark. Conversion rates vary enormously by channel, by industry, and above all by what each team counts as a 'lead' (a form fill, a demo booked, a qualified opportunity), so someone else's 4% tells you nothing about yours. If you have no history yet, run the calculator across a pessimistic and a realistic band — say 2% and 8% — and plan your budget against the pessimistic end.
Is 3:1 LTV:CAC a rule?+
No — it's a widely used SaaS heuristic, not a law. The rough logic: below about 3:1 the unit economics are usually too thin once service, support, and overhead costs come out of that lifetime value; far above 5:1 you may be under-investing in growth that a competitor will happily fund instead. Your right ratio depends on gross margin, payback tolerance, and how much cash you have. That's exactly why the ratio is an editable input here rather than a fixed constant — treat it as a number to argue about, not to obey.
Should CAC include salaries or just ad spend?+
Fully loaded CAC — media spend plus tools plus the team's time spent acquiring customers — is the honest number, and it's the one that belongs in a comparison against LTV. Media-only CAC flatters every channel, because the ad platform's invoice is rarely the whole cost of a lead. Practically: fold the loaded costs into the cost-per-lead input if you can (total monthly acquisition cost divided by leads generated gives a blended, fully loaded cost per lead), and the implied CAC this calculator reports will be fully loaded too.