How much should I spend on Meta Ads?

Meta Ads is an algorithm-driven platform. The algorithm learns who to show your ads to by analysing which users convert. Without enough conversion data, it cannot optimise effectively - and your money is essentially being spent on guesswork. The critical threshold is the learning phase. Each ad set needs approximately 50 conversion events per week to exit the learning phase and enter stable delivery. If your target cost per acquisition is £30, that means you need roughly £1,500 per week in ad spend on that single ad set to hit 50 conversions. For most UK businesses running lead generation or ecommerce campaigns, £1,500-3,000 per month is a reasonable starting point. This allows you to run 1-2 ad sets with enough budget to gather meaningful data. It is not enough for extensive testing, but it is enough to prove whether Meta Ads can work for your business. Below £1,000 per month, the data is too thin. Campaigns stay in the learning phase, performance fluctuates wildly, and it becomes nearly impossible to distinguish signal from noise. If your budget is below this threshold, consider whether Meta Ads is the right channel, or whether that budget would be better deployed on Google Search where intent-based targeting requires less data to perform.

Once you have established a working budget, how you allocate it across campaign types matters as much as the total amount. A proven allocation framework is 70/20/10: 70% on prospecting - campaigns targeting new audiences who have never interacted with your brand. This is where growth comes from. Prospecting campaigns drive top-of-funnel awareness and generate new leads or customers. They typically show the lowest ROAS but are essential for sustainable growth. 20% on testing - dedicated budget for trying new creative, new audiences, new offers, and new formats. Without a testing budget, your campaigns will eventually fatigue. Creative and audiences degrade over time. The testing budget ensures you always have fresh assets and insights feeding into your core campaigns. 10% on retargeting - campaigns targeting people who have already visited your site, engaged with your content, or started but not completed a purchase. Retargeting typically shows the highest ROAS, but it only works if prospecting is feeding new users into the top of the funnel. Over-investing in retargeting is one of the most common mistakes - it looks efficient on paper but it is not driving incremental growth. This ratio shifts as you scale. Early-stage advertisers may lean more heavily into testing (60/30/10). Mature accounts with proven creative libraries may shift to 75/15/10.

Scaling Meta Ads budget is not as simple as adding more money. The algorithm is sensitive to changes, and sudden budget increases can reset the learning phase and destabilise performance. The general rule is to increase budgets by no more than 20-30% every 3-5 days. This gives the algorithm time to adjust delivery without re-entering the learning phase. If you need to scale more aggressively, consider duplicating your best-performing ad sets at higher budgets rather than increasing the existing ones. Before scaling, ensure the fundamentals are solid. You should only increase spend when you have at least 2-3 ad sets that have exited the learning phase and are delivering consistent results over a 7-14 day period. Scaling a campaign that has not yet proven itself just amplifies the problem. Signs you are ready to scale: - Consistent CPA below your target for 7+ days - Ad sets comfortably out of the learning phase - Creative is not showing signs of fatigue (rising frequency, declining CTR) - Your landing page conversion rate is stable - You have fresh creative ready to deploy as you increase volume Signs you should not scale yet: - CPA is volatile day to day - Ad sets are still in or re-entering the learning phase - You are running fewer than 3 distinct creative concepts - Your landing page is not converting at an acceptable rate Budget is only one lever. Often, improving creative quality or landing page conversion rate has a larger impact on results than simply spending more.