If you’ve been running campaigns in Google Ads for a little while, you’ve probably had that “wait, what?” moment. You log in, look at your spend, and see a number that’s higher than the daily budget you set.
Did Google just ignore your instructions? Are you about to blow through your marketing funds? Don’t worry, you’re not alone. This is one of the most common questions in the digital marketing world, and it all comes down to how Google interprets your budget.
Budget Basics: Over-Delivery
For years, when you entered a daily budget, Google would quietly turn that number into a monthly budget by multiplying it by 30.4, the average number of days in a month. That gave the system an upper limit for the month. From there, the algorithm allowed up to 20% more than your daily number on any given day.
That “extra” spend is called over-delivery, and the idea was simple: traffic isn’t the same every day, so Google would spend a little more when searches and conversions were high, then even it out on slower days. The goal was to maximize your visibility while keeping your monthly spend in check.
What’s New for Google Ads Spend
Google quietly rolled out an update to this system in 2024. That 20% cushion wasn’t enough for the volume of traffic some advertisers were missing, so they raised the ceiling. Now, Google may spend up to 100% over your daily budget if there’s an opportunity to capture more traffic.
So, if you’ve set a daily budget of $500 in a competitive market, Google could spend as much as $1,000 on a single day, as long as the total for the month doesn’t exceed your budget multiplied by 30.4.
Why This Can Feel Tricky
The premise behind over-delivery makes sense: let your ads shine when the audience is ready. But the system isn’t perfect, especially for small business owners or anyone testing campaigns without a clear monthly plan.
If you change your budget several times in one month, the math for Google’s “monthly charging limit” gets messy fast. And while Google offers over-delivery credits if you’re ever charged above the monthly limit, the back-end calculations can still create headaches for advertisers who are watching every dollar.
Protecting Your Budget
In my experience, Google rarely reverses these kinds of updates, so the best strategy is to work with them rather than against them. A few practical tips.
Start with a clear monthly budget for each campaign, not just a daily amount. That gives you a realistic picture of your spend and helps you decide how much flexibility you’re comfortable with.
Monitor your accounts closely during the first week or two of a new campaign so you understand how traffic fluctuates day by day.
If you’re unsure how to calculate or manage your marketing budget, reach out to someone who works with Google Ads regularly, they can help you set limits and interpret spend data so you’re not caught off guard.
Google isn’t ignoring your daily settings; it’s trying to align spend with demand, making sure your ads show up on the days that matter most. Over a month, the math works out, but it’s easy to feel uneasy when you see spend that’s double your budget on a busy day.
Take a step back, focus on the monthly totals, and make sure your budgets are set with a clear ceiling in mind. With thoughtful planning, Google’s over-delivery system can actually work in your favor, helping you capture valuable traffic without losing sight of the bigger picture.