How the calculator works
Start from the goal, not from the budget. Enter how many new customers or orders you want each month and what one lead or click costs you. The calculator works backwards to the budget, the number of leads and clicks you need, and what the ads bring back.
Lead generation
Online store
The daily budget is the monthly budget divided by 30.4, the average number of days in a month. Return on ad spend (ROAS) is expected revenue divided by the budget, and profit after ads is revenue times margin, minus the budget.
Meta's learning phase and your budget
When you start an ad set or make a significant edit, Meta's delivery system needs time to learn who to show your ads to. Meta says an ad set usually leaves this learning phase after about 50 results in the week after its last significant edit. A result here is what the ad set is optimized for, for example a lead or a purchase.
The calculator checks how many of those results your budget brings each week and splits them across your ad sets. Below about 50 a week per ad set, Meta will likely show the status Learning limited. Meta says this is not a penalty, but a sign that the budget is not spent as well as it could be. Besides a low budget, Meta lists a small audience, a low bid or cost control and results that happen rarely as common causes.
- Fewer ad sets: Meta's first advice for Learning limited is to combine ad sets, so the results are not split between them.
- Fewer edits: a new ad, a change of targeting, creative or optimization event, or a pause of 7 days or more starts learning again. A big budget change can do the same.
- A result that happens more often: if purchases are rare, Meta suggests optimizing for an event that happens more often, for example add to cart instead of purchase.
- Patience: with a small budget, judge results over a few weeks, not day by day.
How to choose realistic numbers
- Cost per lead or per click: take it from your own ad account for the last 30 to 90 days. If you have never run ads, start with the example and update it after the first weeks.
- Leads that become customers: count your last inquiries and how many of them bought. Do not guess from what others say.
- Value of one customer and order value: use what an average customer pays, not your most expensive offer.
- Margin: what is left after the product or service costs, before ads.
- When in doubt, be careful: take the higher cost and the lower conversion. The scenarios show how much the budget moves.
The online store example (about €0.05 per click, 1.5 purchases per 100 visits and €40 per order) is close to what Meta reported in 2026 for Serbian online stores we run ads for. Treat it as an example: costs differ a lot between industries, seasons and countries.
In our experience, a new business usually starts with €400 to €500 a month for ads. We treat the first month as a test: we see the real cost per lead or purchase and then plan the budget from your own numbers. It is a starting point, not a promise of results.
FAQ
How much should I spend on ads?
As much as your goal needs, at a cost per result you can afford. Work out the budget first, then look at the most you can pay per lead or purchase. If your real cost is above that limit, a bigger budget only makes the loss bigger.
What if my budget gives fewer than 50 results a week?
That is normal for many small businesses and it does not mean the ads will not work. Keep one ad set, avoid frequent edits and give the campaign a few weeks before you judge it. If purchases are rare, Meta suggests optimizing for an event that happens more often, such as add to cart.
Is the daily budget spent exactly every day?
No. Ad platforms spend more on some days and less on others, so check spend over a week or a month, not day by day.
Does this work for Google Ads too?
The budget math does. The learning phase check is for Meta. Google Ads also shows a learning status when you start or change automated bidding, but with its own rules.
The tool only uses what you enter. Nothing is sent or stored.