How to Determine How Long to Run Facebook Ads for Optimal Results

Recently, I wrapped up my One Ad Wonder live workshop series for e-commerce business founders looking to upskill and run Facebook ads. During the series, one of the most frequently asked questions was, "How long should I let my ad run before turning it off if it's not performing?" So in today's episode, I will discuss how to decide when to stop a Facebook ad that isn't performing and dive into Facebook advertising strategy and learn how to optimise your ad spend.

Here’s a rewritten version of your content with the keyword “Run Facebook Ads” naturally included 4–5 times while keeping it clear, concise, and engaging:

Understanding the Fundamentals of Facebook Ads

Before you dive into your campaigns, it’s essential to understand the core concepts when you run Facebook ads:

KPI Goals

Define clear business goals for each campaign, focusing on Key Performance Indicators (KPIs) that measure success. Whether it’s sales, leads, or website traffic, knowing your KPIs ensures your Facebook ads are working toward meaningful outcomes.

Cost Per Result (CPR)

Facebook Ads Manager tracks the CPR, showing how much you spend to achieve a specific result, such as a sale or lead. This metric is crucial when you run Facebook ads efficiently and avoid overspending.

Return on Ad Spend (ROAS)

ROAS calculates the revenue generated relative to your ad spend. It’s a vital benchmark to determine whether your Facebook campaigns are profitable.

How Long Should You Run Facebook Ads?

Focus on Dollars Spent, Not Just Time

Many ask, “How long should I let my ad run?” The better question is how much budget your ad has spent and whether it meets your goals. When you run Facebook ads, duration alone doesn’t indicate success; metrics do.

Set Your Goal Cost Per Sale

Before evaluating an ad, determine your goal cost per sale (or cost per purchase). This number guides your decision-making when you run Facebook ads. A general rule: allocate about one-third of your average order value for ad spend.

Example:
Selling a $150 dress? Spend up to $50 on ads to achieve a sale, giving a ROAS of 3.

Evaluate Ad Performance

Once your goal is set, assess your campaign:

Spend Adequately: Don’t judge until your ad has spent at least the goal cost per sale.
Analyse Key Metrics: Look beyond sales—monitor add-to-cart actions and click-through rates (CTR).
Decision Time: If promising metrics exist but no sales, let your ad run until it reaches twice the goal cost per sale.

Example: If your goal was $50, spend $100 before revising.

Revise if Needed

If your ad still underperforms after twice the target spend, redesign elements such as visuals, copy, or headlines.

Avoid the Pitfall of Low Daily Budgets

A low daily budget (e.g., $1/day) can delay insights and hinder performance. When you run Facebook ads, ensure your budget allows your campaigns to reach the goal cost per sale quickly for meaningful evaluation.

Example: Spending $14 over two weeks at $1/day isn’t enough to gauge success. Adjust your budget to reach your target faster.

Key Takeaways

When you run Facebook ads, success isn’t about how long an ad has been live—it’s about meeting your predefined cost per sale goals. Monitor key metrics, set realistic budget targets, and allow campaigns the space to perform before making changes. Focus on dollars spent and results achieved, not just elapsed time, to run Facebook ads that truly drive business growth.

Need help? Check out my Facebook Ad courses.