If you've googled this question, you've probably seen answers ranging from "$5 a day is fine" to "10% of revenue or don't bother." Both can be right — for different businesses. Here's how to actually find your number.

Start with the math, not the budget

Work backwards from a customer. Say you're a med spa and a new client is worth $400 on their first visit. If your booking rate from leads is 1 in 4, a lead is worth about $100 to you. That means you can pay $30-50 per lead and still be comfortably profitable. If you don't know these two numbers — customer value and lead-to-customer rate — figure them out before spending a dollar. Everything else depends on them.

The minimum that actually teaches you something

Meta's algorithm needs data to optimize. Spend too little and your campaign never exits the learning phase — you're paying full price for random results. As a rule of thumb, your daily budget per campaign should cover several times your expected cost per lead. For most local service businesses, that lands around $500-$1,500/month as a realistic test budget. Below roughly $300/month, results are usually too noisy to judge, and you're better off putting the money into your Google Business Profile and reviews first.

The 90-day rule

Give a test three months, not three weeks. Month one is learning and creative testing. Month two is optimization — cutting losers, funding winners. Month three tells you your true cost per lead. Judging Meta ads on week two is the most common way small businesses waste money — they turn ads off right before the data becomes useful, then conclude "ads don't work."

When to scale (and when to stop)

Scale when your cost per lead has been stable for 3-4 weeks AND your follow-up can handle more volume. Increase budget 20-30% at a time — doubling overnight resets the algorithm's learning. Stop (or fix something else first) when leads come in but don't book: that's not an ads problem, that's a follow-up or offer problem, and more budget will just make it more expensive.

The part nobody talks about

The businesses that win with Meta ads usually don't have better ads — they have faster follow-up. A lead contacted within 5 minutes is dramatically more likely to book than one contacted the next day. Before you raise your budget, make sure every lead gets an instant response, even after hours. That single fix often does more than doubling ad spend.

Want a second opinion on your numbers? We'll look at your ad account in a free 15-minute call and tell you exactly what we'd change first.