How do you calculate budget pacing?
Say the October budget across Google Ads, Meta and TikTok is €62,000 and the platforms report €24,800 spent by the end of 11 October. October has 31 days, so 20 remain.
| Step | Result | Calculation |
|---|---|---|
| Plan to date | €22,000 | €62,000 × 11 ÷ 31 |
| Pacing | 112.7% | €24,800 ÷ €22,000 |
| Run rate | €2,254.55 a day | €24,800 ÷ 11 |
| Projected month-end | €69,891 | €2,254.55 × 31 |
| Over budget | €7,891 (12.7%) | €69,891 − €62,000 |
| Daily budget to land | €1,860 | (€62,000 − €24,800) ÷ 20 |
At 12.7% ahead the month is drifting. Landing on €62,000 means cutting combined daily spend from about €2,255 to €1,860, a 17.5% cut. That is bigger than the ±15% daily change the account in our product demo lets Nupact make without approval, so in Nupact this cut would wait for a person to approve it.
How far off pace is too far?
| Pacing vs plan | Status | What to do |
|---|---|---|
| 95% to 105%, both included | On pace | Leave budgets alone. Most of this gap is daily noise. |
| 85% up to 95%, or above 105% up to 115% | Drifting | Check whether the weekday pattern explains it, and correct the budget if the gap holds for three days. |
| Below 85% or above 115% | Off pace | Change daily budgets today, and look for the campaign carrying the gap. |
Behind plan deserves as much attention as ahead: a campaign at 80% of plan with a good return is headroom you lose at month-end. Before raising its daily budget, check that it can absorb more, since a campaign held back by its bid target or a disapproved ad will not spend more because its budget went up.
Where does straight-line pacing go wrong?
The calculator assumes every day of the month is worth the same. Four things break that assumption.
Weekdays
A B2B search campaign that spends half as much on Saturday and Sunday reads behind every Monday morning and ahead every Friday, with nothing wrong. The fix is a plan to date built from each campaign's weekday curve.
Planned peaks
If a sale on the 25th should take 30% of the month's budget, a straight-line plan reports the first three weeks as ahead of a pace you never intended. Put the planned peak into the plan, or pace the sale as its own flight.
Platform overdelivery
Google Ads can spend up to twice a campaign's average daily budget on one day, and Meta up to 75% over. On day 3, one 2× day on Google puts a campaign a third ahead. Our guide to ad platform overspend sets out both rules and how to alert on them.
Platform calendars
Google's monthly charging limit is 30.4 times the average daily budget whatever the length of the month. Set the daily budget to the monthly budget divided by 31 and, in October, Google can bill at most 98% of your plan (30.4 ÷ 31). In February the limit is 108.6% of 28 days' budget. Meta caps spending per Sunday-to-Saturday week, and those weeks run across month boundaries, so the last days of one month and the first days of the next share one limit.
How do Google Ads and Meta daily budgets pace over a month?
Each platform lets a single day run past the daily budget and caps a longer window instead: Google allows up to 2× on a day and bills at most 30.4× per calendar month. Meta and TikTok's Dynamic Daily Budget both cap the Sunday-to-Saturday week at 7× the daily budget, with up to 175% on a single day on Meta and 125% on TikTok. Our guide to ad platform overspend has the full table with sources, including Meta's ad set budget sharing and TikTok's automatic budget increases.
Google Ads budget pacing. Google's advice for a monthly budget is to "divide that number by 30.4" to get the average daily budget (Google Ads Help), which matches the 30.4 times cap on monthly billing. After a mid-month change, the rest of the month paces to the new daily budget times the remaining calendar days (How budget changes take effect). Since 1 June 2026, campaigns whose ad schedule switches off whole days also pace to the full 30.4 times the daily budget, so a campaign that runs 20 days a month needs a lower daily budget than before to spend the same amount (Google Ads Help on ad scheduling).
Meta ads budget pacing. Meta treats a daily budget as a target over the Sunday-to-Saturday week. With ad set budget sharing switched on, Meta may also pass up to 20% of a daily budget to other ad sets, so one ad set can spend up to 210% of its budget on a day and 8.4 times it in a week. Weeks cross month boundaries, so the weekly cap can straddle two months. A campaign spending limit caps a campaign's lifetime total until you raise or reset it by hand. The ad account spending limit is a lifetime limit too, and some advertisers can set it to reset automatically on the 1st of each month, which is the closest Meta gets to a monthly ceiling.
Campaign budget optimisation and shared budgets. Meta's Advantage+ campaign budget, formerly campaign budget optimisation, spreads one budget across ad sets in real time and may put most of it into one ad set; Meta says to judge results at campaign level. Pace it as one line, and do the same for a Google shared budget, where one average daily budget feeds several Search, Shopping, Display or Video campaigns.