How much should you spend on ads each month? Working out a minimum budget for Meta and Google
The minimum budget is set by how many conversions the system needs to learn, not by a round number. On Meta, an ad set usually needs about 50 optimization events a week to exit the learning phase. On Google, the recommendation is to judge a smart bidding campaign over a period with at least 30 conversions. Multiply the number of conversions by the expected cost per conversion, and you get the budget at which the systems really work. When your budget is smaller, narrow down: fewer campaigns, one platform, or an earlier conversion event.
Why “how much are you willing to spend” is the wrong question
Most businesses set an ad budget by feel: “Let’s start with 3,000 and see.” The problem is that Meta and Google don’t work by amount. They work by data. Every lead or purchase that comes in teaches the system who to show the ads to. With too few conversions, the system guesses, and results jump from week to week.
So the right question is: how many conversions does the system need to learn, and how much does it cost to get them?
How many conversions Meta needs
On Meta, every ad set goes through a learning phase. According to Meta, an ad set usually exits it after about 50 optimization events a week. An optimization event is what you asked the campaign to bring: a lead, a purchase or an add to cart. A significant change to the ad set, like a big change in budget or audience, sends it back into learning.
What this means: a budget that brings 10 leads a week to an ad set isn’t enough for the system to stabilize. It will keep searching.
How many conversions Google needs
On Google, smart bidding campaigns such as Target CPA can start even without history. But Google recommends judging performance over the last 30 days, in a period with at least 30 conversions. With fewer than that, the numbers don’t say much yet.
The minimum budget formula
| Platform | Minimum monthly budget |
|---|---|
| Meta | 50 conversions × expected cost per conversion × 4.3 weeks, per ad set |
| 30 conversions × expected cost per conversion, per campaign |
An illustrative example: a business with an expected cost per lead of ₪60. On Meta, one ad set aimed at leads needs 50 × ₪60 = ₪3,000 a week, about ₪13,000 a month. On Google, one campaign needs 30 × ₪60 = ₪1,800 a month to reach 30 conversions. The numbers are for illustration only. Check the expected cost per conversion by industry, by the business’s past data, or in a first test month.
Before you calculate, it’s also worth knowing how much you can pay for a lead. If the expected cost is higher than the business can afford, the problem isn’t the budget but the offer, the price or the page.
What to do when your budget is below the minimum
- Fewer ad sets: one ad set with 50 conversions a week is better than five ad sets with 10 conversions each.
- One platform first: instead of splitting ₪5,000 between Meta, Google and TikTok, start where your customers search or scroll, and expand once there are results.
- An earlier conversion event: in a small store, you can start by optimizing for add to cart or initiate checkout, which happen more often than purchases, and switch to purchases once there’s enough data.
- Google before Meta, when there’s demand: in a business people already search for on Google, you can reach 30 conversions on a smaller budget.
And what about the agency fee?
The media budget and the management fee are two separate things. When you calculate what a new customer costs, add both together and divide by the number of customers closed. Here we detailed what campaign management costs and which pricing models exist. On a very small media budget, the management fee becomes a large part of the cost, which is why our work starts from ₪10,000 a month in media budget.
Want to know where you stand? We’ll check the numbers against your account, free of charge.
Get a fit checkFrequently asked questions
What’s the minimum budget for advertising on Facebook?
There’s no single amount. On Meta, an ad set usually needs about 50 optimization events a week to exit the learning phase. Multiply 50 by the expected cost per lead or purchase, and you get the weekly budget per ad set.
Can you start with a small budget and grow later?
Yes, as long as you narrow down: one platform, one ad set, and sometimes an earlier conversion event. When you scale up, do it gradually, because a big budget change can send the ad set back into the learning phase.
How long should you wait before judging a campaign?
On Google, the recommendation is to look at a 30-day period with at least 30 conversions. On Meta, don’t judge an ad set before it has exited the learning phase, unless it’s clearly bringing no results at all.
Sources
Founder of SMOLANSKI Media. 14 years in advertising management, 10 of them at Israel’s leading media and advertising agencies.
Related services: Campaigns for lead-gen businesses · Campaigns for online stores · Facebook and Instagram campaign management · Google campaign management
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