Facebook ad budget calculator
To test new ads you need enough spend on each one to tell a winner from a loser. A common rule of thumb is to let each ad spend two to three times your target CPA before you judge it. Six new ads at a £30 target CPA and a 2x rule need about £360.
Enter your target CPA, how many ads you want to test and how many days you have, and the calculator gives you the testing budget and the daily budget to set in Ads Manager.
Plan a creative test
Testing budget
£360
£60 per ad across 6 ads.
Daily budget for the test
£51
Over 7 days.
Monthly budget at your target CPA
£3,000
About £99 a day.
These are planning numbers. Giving each ad two to three times your target CPA before you judge it is a rule of thumb, not a Meta rule. Worked out in your browser.
How the numbers work
Spend per ad = target CPA x the multiple you choose. Testing budget = spend per ad x number of ads. Daily budget = testing budget / days.
The monthly figure is simpler: the sales you want from ads each month, times your target CPA. If that number is more than you can spend, either the goal or the CPA has to move.
Making a test budget go further
The cheapest test is the one where every ad has a real chance. Start from formats that have already won on Meta, change one thing at a time, and cut an ad once it has spent its share without a sale.
If you do not know your target CPA yet, use your break-even CPA from /tools/break-even-roas-calculator.
Frequently asked questions
- How much should I spend to test a Facebook ad?
- A common rule of thumb is two to three times your target CPA per ad before you decide. Below that, a single lucky or unlucky sale can swing the result.
- How many ads should I test at once?
- Enough to compare real differences, usually three to six new ads per test. More than that splits a small budget too thinly.
- How long should a creative test run?
- Long enough for each ad to reach its spend threshold, and ideally a full week so weekday and weekend behaviour both count.