Ad budget planner
How this calculator works
First, customer payment minus the direct cost of serving them gives the contribution available before acquisition, fixed overhead and profit. It is not net profit. For a subscription, we multiply this by expected paid months to estimate lifetime contribution.
The total acquisition ceiling is the smaller of the amount you allow from lifetime contribution and the contribution expected inside your recovery window. For monthly subscriptions, the timing model assumes a constant monthly cancellation probability of 1 / expected paid months, with the first month paid. A free trial delays the start of paid contribution. We use 30 days per month, subtract the trial duration from the recovery window, and prorate contribution for a partial paid month. If the trial uses the whole window, nothing is available to recover acquisition costs within it. Trial length does not itself reduce lifetime contribution; trial delivery costs belong in other acquisition costs. Without a trial, expected contribution through month T = monthly contribution × expected paid months × [1 − (1 − 1 / expected paid months)^T]. Real retention may differ; expansion, variable pricing, annual prepayment and collection delays need a more specific model.
We subtract other acquisition costs to find the amount available for ads. Affordable average CPC = ad budget per paying customer × click-to-paying-customer rate. Estimated ad cost per customer = CPC / that rate. The inquiry path multiplies click-to-inquiry and inquiry-to-paying-customer rates.
The investment projection divides the total acquisition budget by estimated total cost per acquired customer, including other acquisition costs. It multiplies expected customers by average payment for starting revenue and, for subscriptions, by expected paid months for lifetime revenue. Delivery costs and acquisition spend are deducted separately to show what remains before fixed overhead and tax. Fractional customers represent expected averages; the projection does not establish market size, class capacity or stable acquisition costs at larger budgets.
The single-purchase option counts only the first sale and its direct costs, with no assumed repeat purchases. Check when cash arrives. All results are planning estimates. Examples and scenario rates are invented for teaching, not business results or industry benchmarks.
Read the beginner’s guide and examples · Background on subscription economics