Ad Budget Calculator
Enter the number of sales you want, your conversion rate and what a click costs. The calculator shows the clicks and the ad budget you would need, your daily budget and the return on ad spend.
How to use this Ad Budget Calculator
- Enter the number of sales you want from ads in the period.
- Enter your conversion rate, the share of clicks that lead to a sale.
- Enter the average cost per click for your channel.
- Enter your average order value and the number of days.
- Press Calculate to see the budget, the daily spend and the ROAS.
How to calculate an ad budget
Work backward from the sales you want to the clicks and then to the cost.
- Clicks needed = sales / conversion rate
- Ad budget = clicks x cost per click
- Daily budget = ad budget / days
- Cost per sale = ad budget / sales
- ROAS = revenue / ad budget
Worked example
You want 100 sales in 30 days. Your conversion rate is 2%, so you need 100 / 0.02 = 5,000 clicks. At $1.20 per click the budget is $6,000.00, which is $200.00 a day. The cost per sale is $60.00. With an average order of $90 the revenue is $9,000.00 and the return on ad spend is 1.50x.
A ROAS of 1.5x looks fine on revenue, but you must compare it with your margin. If your gross margin is 40%, then $9,000 of revenue is only $3,600 of gross profit, which does not cover the $6,000 of ads on this order alone. The break-even ROAS is one divided by your margin, so test whether the plan works for you before you spend. Start with a small test budget to learn real conversion and click costs, then scale.
Assumptions & limits
- The conversion rate and the click cost are your estimates. Real values depend on the audience, the offer, the landing page and the season.
- The calculator treats cost per click as constant. In practice it rises as you spend more on the same audience.
- Repeat purchases and lifetime value are not counted. If customers buy again, the true return is higher.
- It does not include creative, agency or tool costs.
- ROAS uses revenue, not profit, so compare it with your break-even ROAS.
Frequently asked questions
How do I calculate an ad budget?
Divide your target sales by your conversion rate to get clicks, then multiply by the cost per click.
What is ROAS?
Return on ad spend is the revenue from ads divided by the ad spend.
What ROAS do I need?
You need at least your break-even ROAS, which is one divided by your gross margin. The Break-Even ROAS Calculator on this site can work it out.
How much should I spend on ads?
Start from your sales goal and your numbers, then begin with a test budget and scale what works.
Why is my real cost per sale higher?
Conversion rates often start lower than expected, and click costs can rise as you scale.
Should I include lifetime value?
If customers buy again, yes. It can justify a higher cost per sale, so look at CLV too.
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Last updated: November 2026