eCommerce Marketing Budget Calculator

Key facts

• Ad budget = (revenue goal divided by AOV) divided by conversion rate, times cost per click.
• Break-even CPC = AOV times conversion rate times contribution margin.
• Established brands spend 10% to 20% of revenue on marketing; launch phases run higher.
• Ad spend goes out before the revenue it creates comes back; the cash timeline shows the gap.

Last updated September 7, 2026. Fee presets, payout timing, and Onramp Funds eligibility and fee example checked against the published sources listed at the end of this page.

How to use the marketing budget estimator

Most budget planning starts with a number someone is comfortable spending. This estimator works the other way. Enter the revenue you want ads to produce, your average order value, conversion rate, and cost per click, and it calculates the orders and clicks required, the budget that buys them, and whether that budget is still profitable after your contribution margin.

• Average order value: revenue divided by orders over the last 30 to 90 days.
• Conversion rate: orders divided by ad clicks. Amazon sponsored products often convert at 8% to 15%. DTC sites from paid social typically convert at 1% to 3%.
• Cost per click: pull it from your ad platform for the campaigns you plan to scale, not the account average.
• Contribution margin: what is left of each revenue dollar after product cost, shipping, and marketplace fees, before ad spend.
• Repeat purchases: optional. If customers buy again, you can afford a higher first-order acquisition cost.

What makes this calculator different

Every number on this page has a time dimension. Other calculators tell you whether something is profitable; this one also shows the cash timeline: when the money goes out, when the platform pays you back, the week your cash position bottoms out, and how much you need to cover the gap. Three other things worth knowing:

• Platform presets: choose Amazon, Shopify, Walmart, TikTok Shop, WooCommerce, BigCommerce, Squarespace, Shopline, or Stripe and the fee and payout-delay fields fill in from published rate cards. Every preset is editable.
• Import your own export: upload a payments, settlement, or orders report from Amazon, Shopify, Walmart, or TikTok Shop and the calculator fills in revenue, fees, refunds, and payout timing from your actual data. The file is read in your browser and never uploaded anywhere.
• Compare two scenarios: duplicate your inputs into Scenario B, change one thing, and see both results and both cash curves side by side.
• Share or save: copy a link that reopens the calculator with your exact numbers, or save the result as a PDF. Your inputs carry over to the other calculators on this site, and nothing is stored on our servers.

The formulas

Orders needed = revenue goal divided by AOV. Clicks needed = orders divided by conversion rate. Budget = clicks × CPC. Cost per acquisition = budget divided by orders. Required ROAS = revenue goal divided by budget. Break-even CPC = AOV × conversion rate × contribution margin, the most you can pay per click before a first order loses money.

How to read the result

Compare your current CPC with the break-even CPC. If you are paying close to break-even, scaling spend will grow revenue and shrink profit at the same time. The two levers that move the budget most are conversion rate and AOV: a half-point improvement in conversion rate often saves more than any bid optimization, and a bundle or free-shipping threshold that lifts AOV lowers the required budget without touching the ads.

Budget is rarely the constraint, timing is

Sellers usually know the ad spend that would work. The problem is that it has to go out before the sales come in, on top of the inventory that also had to be paid for early. Onramp Funds advances capital against your sales so you can fund a launch or a seasonal push up front and repay as a percentage of the revenue it produces. Flat fee disclosed upfront, no personal credit check. See how much capital your combined revenue unlocks.

Sources

• Onramp Funds: how it works, eligibility, and fee example

Frequently asked questions

What percentage of revenue should an ecommerce brand spend on marketing?

Established brands commonly spend 10% to 20% of revenue. Brands in a growth or launch phase often run 25% to 35% for a defined period, which only works if contribution margin can absorb it.

What is a good ROAS?

Divide 1 by your contribution margin. At a 40% margin, a 2.5x ROAS breaks even, so 3.5x to 4x is a healthy target.

Does this estimator store my data?

No. Calculations run in your browser and nothing is saved.