Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Required ad budget
$67,857
Implied cost per acquisition
$79.17
Allowable CPA
$46.20
Orders needed
857
Clicks needed
35,714
Implied ROAS
1.77
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter revenue target ($).
- 2Enter average order value ($).
- 3Enter gross margin (%).
- 4Enter landing page conversion rate (%).
- 5Enter average cost per click ($).
- 6Enter target profit share of margin kept (%).
- 7Read your required ad budget on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Work backwards from the target, not forwards from the budget. Your allowable CPA falls straight out of order value and margin, and that number sets the ceiling on every bid.
Worked example
Using the values the calculator loads with:
Inputs
- Revenue target: 120000 $
- Average order value: 140 $
- Gross margin: 55 %
- Landing page conversion rate: 2.4 %
- Average cost per click: 1.9 $
- Target profit share of margin kept: 40 %
Results
- Required ad budget: $67,857.14
- Implied cost per acquisition: $79.17
- Allowable CPA: $46.20
- Orders needed: 857.14
- Clicks needed: 35,714.29
- Implied ROAS: 1.77
What each field means
Inputs
- Revenue target ($)
- The revenue target used in the calculation, measured in $. Starts at 120000 $ so you have a working example on load.
- Average order value ($)
- The average order value used in the calculation, measured in $. Starts at 140 $ so you have a working example on load.
- Gross margin (%)
- The gross margin used in the calculation, measured in %. Starts at 55 % so you have a working example on load. Accepted range: 0–100 %.
- Landing page conversion rate (%)
- The landing page conversion rate used in the calculation, measured in %. Starts at 2.4 % so you have a working example on load. Accepted range: 0.01–100 %.
- Average cost per click ($)
- The average cost per click used in the calculation, measured in $. Starts at 1.9 $ so you have a working example on load.
- Target profit share of margin kept (%)
- The target profit share of margin kept used in the calculation, measured in %. Starts at 40 % so you have a working example on load. Accepted range: 0–100 %.
Results
- Required ad budget
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Implied cost per acquisition
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Allowable CPA
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Orders needed
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Clicks needed
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Implied ROAS
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the ad budget calculator work?
Work backwards from the target, not forwards from the budget. Your allowable CPA falls straight out of order value and margin, and that number sets the ceiling on every bid. The underlying maths is: Budget = Target conversions × CPA; allowable CPA = AOV × margin ÷ target ROAS multiple.
What do I need to enter?
6 values: revenue target, average order value, gross margin, landing page conversion rate, average cost per click, and target profit share of margin kept. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the required ad budget result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Ad Budget Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/ad-budget
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/ad-budget" target="_blank" rel="noopener">Ad Budget Calculator — RevenueLab</a> (2026).</p>
Source: [Ad Budget Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/ad-budget) (2026).