Helpful Toolbox

Ad Budget Calculator

Set the goal — new customers or revenue — and this calculator works backward to the ad budget, leads needed, and maximum cost per lead. Free and private: every number is computed live in your browser.

📖 How it works & FAQ

Plan the budget from the goal, not the gut

Most ad budgets get picked by feel — a round number that seems affordable this month. This calculator flips that: start from the result you want and work backward to the spend it takes. In Customer goal mode, budget equals target customers multiplied by your target cost per acquisition (CAC). In Revenue goal mode, budget equals desired revenue divided by your target ROAS (return on ad spend), and your average order value shows how many customers that revenue represents. Your lead-to-customer close rate then converts customers into the leads you need and a maximum cost per lead (CPL) — the bid ceiling that keeps the whole plan on track. Everything updates live as you type and runs entirely in your browser; nothing you enter is uploaded anywhere.

How to use it

  1. Pick a planning mode: Customer goal (customers × CAC) or Revenue goal (revenue ÷ ROAS).
  2. Enter your target customers and an affordable CAC, or your revenue goal, target ROAS, and average order value.
  3. Set your lead-to-customer rate — the percentage of leads that actually become paying customers.
  4. Read the result cards: required ad budget, expected customers, leads needed, and the maximum CPL you can afford to pay.

FAQ

What CAC should I target?
A common rule of thumb is to keep CAC at or below one third of customer lifetime value. If you do not know lifetime value yet, start with the gross profit on a first order minus the margin you want to keep — that is the most you can pay and still come out ahead on purchase one.
What counts as a good ROAS?
Break-even ROAS is 1 divided by gross margin: at a 50% margin you break even at 2×, so most stores target 3× to 4× to leave room for profit. High-margin services can run profitably at lower ROAS.
Why does max CPL matter?
Ad platforms sell clicks and leads, not customers. If your real cost per lead runs above the max CPL shown here, the budget will run out before you reach the customer goal — lower bids, improve the landing page, or raise the budget.
Is my data private?
Yes. All of the math happens on your device in plain JavaScript; there is no server, no account, and nothing is stored or sent.

These figures are planning estimates only — not professional, financial, tax, or legal advice.