Most small businesses think in monthly budgets. Google and Meta mostly do not. You set a daily budget, both platforms may spend above it on some days, and neither has a simple “stop at £1,000 this month” switch for ongoing campaigns. Here is how the rules work and how to pace against a monthly number.
How Google Ads daily budgets really work
In Google Ads the figure you enter is an average daily budget. Google’s help page on budgets sets two limits:
- On any one day, a campaign can spend up to twice its average daily budget, to catch busier days.
- Across a calendar month, you will not be charged more than 30.4 times the average daily budget.
If delivery runs over those limits, Google does not bill the excess: its page on spending limits says you never pay more than the daily and monthly limits.
| Average daily budget | Most on one day | Most in a month |
|---|---|---|
| £20 | £40 | £608 |
| $25 | $50 | $760 |
| £50 | £100 | £1,520 |
Three things follow:
- Set Google budgets from the monthly figure. Divide the monthly budget by 30.4. £600 a month is about £19.74 a day; $1,000 is about $32.89.
- Short months run hotter. The cap is 30.4 days’ worth whatever the month’s length, so in February Google may spend a little more per day than in a 31-day month.
- Mid-month changes blur the picture. Changing a budget part way through a month changes that month’s limit too. If you raise and cut often, keep your own running total.
Google campaign total budgets
For campaigns with a fixed start and end, Google offers campaign total budgets: one amount for the whole flight instead of a daily figure. They are available for Search, Standard Shopping and Performance Max (up to 90 days) and for Demand Gen and YouTube (up to a year). Google paces spend across the dates, speeding up after quiet days and slowing after busy ones, and does not charge above the total.
That suits a promotion or a seasonal push. For always-on campaigns, it means setting new dates and a new total each period, which is its own job to remember.
Meta daily and lifetime budgets
Meta works in a similar way, with a weekly rather than monthly cap. According to Meta’s help page on daily budgets, a daily budget is an average across the week: on some days Meta may spend up to 75% more than it, but in any calendar week (Sunday to Saturday) it will not spend more than seven times the daily figure.
| Daily budget | Lifetime budget | |
|---|---|---|
| You set | An average per day | A total for set dates |
| Can run over on a day | Yes, up to 75% above | Yes, paced across the dates |
| Capped at | 7× daily per calendar week | The lifetime amount |
| Suits | Always-on campaigns | Promotions with an end date |
A lifetime budget spreads one amount across the dates you choose, which is the closest Meta gets to a monthly budget. See Meta’s overview of budgets for how each is paced. For a monthly figure on daily budgets, divide by the number of days in the month.
Meta’s account spending limit
Meta also lets you set an account spending limit: a ceiling on total spend across every campaign in the ad account. When spend reaches it, ads stop until you reset the amount spent, raise the limit or remove it.
It is a useful backstop, with two catches. It is cumulative, not monthly, so for monthly control you need to reset it on the 1st, every month. And it is blunt: it stops everything at once, including the campaign that was working best.
How to pace against a monthly budget
- Decide a monthly figure per platform. Write it down. It is the number everything else serves.
- Convert it. Google: monthly ÷ 30.4. Meta daily budgets: monthly ÷ days in the month.
- Leave a buffer. Plan to spend around 95%. Over-delivery on the last day, or a late adjustment, then has room to land.
- Check pace every week, and daily in the last week. Expected spend so far is the monthly budget × days gone ÷ days in the month.
- Correct from the remainder. If you are ahead, work out a new daily figure from what is left and the days remaining.
- Add a backstop. Meta’s account spending limit, or Google Ads automated rules or scripts that pause campaigns once spend passes a figure you set.
A worked example: a £1,000 month with 31 days. By the end of day 15 you would expect about £484. If you have spent £560, you are about 16% ahead. The £440 left over 16 days is £27.50 a day, so cut daily budgets to that, allowing for Google’s 2× day and Meta’s 75% day.
| Day of 31 | Expected by now | Actual | Daily budget for the rest |
|---|---|---|---|
| 15 | £484 | £560 | £27.50 |
| 22 | £710 | £820 | £20.00 |
| 28 | £903 | £960 | £13.33 |
Separate snapshots of a £1,000 month, each worked from the full budget.
Underspending matters too. If you are well behind by mid-month, raising budgets sharply for the last week can push spend into weaker auctions. Small, early corrections in either direction beat a late scramble.
The danger is the last few days. A month that looks fine on day 25 can overshoot if a campaign has a busy weekend with budgets set for the first half of the month.
Letting software hold the line
Pacing by hand works if someone checks every day. Most owners do not have that day. Tools can do it instead: Google’s automated rules and scripts, Meta’s spending limit, or a service that watches both. AdsEye is one option. Max, its AI ads specialist, checks spend against each platform’s monthly budget hourly and keeps it on pace. At 97% he pauses that platform’s campaigns until the 1st, or until you switch them back on, so a surprise weekend does not become a surprise bill.
