Why a daily budget is not a daily limit
On most ad platforms, the daily budget is an average, not a ceiling. On a busy day the platform spends more than it, on a quiet day less, and it keeps the total over a week or a month in line. That is why a campaign set to 100 a day can show 170 on a Tuesday without anything being broken.
Each platform publishes its own rule for how far over it can go, and over what period it evens out. This calculator applies the rule for the platform you pick and shows the most you can be charged on one day and over the period that rule covers. Every number below comes from the platform's help pages, linked.
The rules, platform by platform
- Google Ads: for most campaigns the daily spending limit is 2 times the average daily budget, and the monthly spending limit is 30.4 times it, 30.4 being the average number of days in a month. So a 10 budget can spend up to 20 on a day and 304 in a month. From About spending limits. Google says you will never actually pay more than those limits; served cost above them is not billed. Pay for Conversions campaigns have no daily spending limit but are still held to the monthly one.
- Meta: on days with better opportunities Meta may spend up to 75% over a daily budget, so no day goes over 175% of it, and no week ending Saturday at midnight goes over 7 times it. With ad set budget sharing on, Meta may also share up to 20% with other ad sets: its example is up to 210 on a day and 840 in a week on a 100 daily budget. From About daily budgets.
- Microsoft Advertising: the monthly budget limit is the daily budget multiplied by the number of days in the month, so the month you pick matters (28 to 31 days). Microsoft calls the daily budget a target and says it usually keeps overspend to less than 100% above the daily limit. That is not a promise, so the calculator marks the daily figure as a usual maximum. From Microsoft's budget and bid strategies guide.
- LinkedIn: daily spend might be up to 100% higher than the daily budget. On a continuous schedule, spend is paced over a Monday to Sunday week and stays within 7 times the daily budget. With a start and end date, total spend stays within the daily budget times the days in the schedule: LinkedIn's example is 3,100 for 100 a day through January. From Campaign and ad set budgets.
- TikTok: a standard daily budget is the maximum TikTok spends per day, per About daily budgets. With Dynamic Daily Budget on, it may spend up to 25% more on good days, with weekly spend from Sunday to Saturday capped at 7 times the daily budget. TikTok's example: 50 a day may spend 62.50 one day and at most 350 in the week.
- Pinterest: with Performance+ daily budgets, Pinterest tries its best to spend no more than 125% of the daily budget in a day, and average daily spend from Sunday to Saturday is no more than the daily budget. From Set up a campaign budget. "Tries its best" is not a cap, so the daily figure is marked as a usual maximum.
When the budget changes mid-period
Changing a budget part way through resets the sum, and each platform documents how:
- Google Ads caps the rest of the month at the new daily budget times the calendar days left. Its example: a 5 budget in November, 103 spent by the 24th, then raised to 10, can charge at most 103 plus 10 times 7 days, which is 173. On the day of the change, the daily limit uses the highest budget you set that day. From How budget changes take effect.
- Microsoft Advertising uses month-to-date spend plus the new daily budget times the days remaining, including today. Its example: 250 spent, changed to 10 on July 15th, gives 250 plus 10 times 17, which is 420.
- Meta takes the new daily budget, multiplies it by the days left in the week, and adds up to 25% of the daily budget. Its example: dropping from 100 to 50 at midnight on Wednesday means at most 212.50 from Wednesday to Saturday. What was spent earlier in the week does not change that figure. From About changing your daily budget.
The calculator counts the day of the change as a day left, because both Google's and Microsoft's examples do.
Working backwards from a monthly budget
If finance gives you a number for the month, the daily budget that respects it depends on the platform. On Google Ads, divide by 30.4: a monthly budget of 3,040 is a daily budget of 100, and the monthly charging limit then lands exactly on 3,040. On Microsoft, divide by the days in that month: 3,000 in a 30-day month is 100 a day. On Meta, LinkedIn, TikTok and Pinterest the rules are weekly or per day, so dividing by the days in the month gives a daily budget that averages out to your number. The calculator rounds down to the cent so the result never tips you over.
What this calculator does not do
It does not read your ad account, and it cannot tell you what a campaign will actually spend: only the most the platform's published rule allows. Lifetime budgets, shared budgets on Google and Microsoft, and campaign types with their own rules are outside it. It also takes no view on taxes, currency conversion or invoicing thresholds. Platforms change these rules from time to time, so each figure links to the page it came from.
If you would rather not watch the pacing yourself
Hermoso is marketing on autopilot. It makes the ads, then builds campaigns on your own Meta, Google and other ad accounts from a plain request, such as a paused Meta campaign around a new ad at 30 a day. Everything is created paused, so nothing spends until you turn it on. It works in the web app, or inside Claude, ChatGPT and Cursor through its MCP server, and the launch a Meta campaign workflow shows the steps.
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Frequently asked questions
Can Google Ads spend more than my daily budget?
Yes. For most campaigns Google can spend up to 2 times the average daily budget on a day, and holds the month to 30.4 times it. Google says you are never billed more than those spending limits.
How much over the daily budget can Meta spend?
Up to 75% on a day, so 175% of the daily budget at most, and never more than 7 times the daily budget in a Sunday to Saturday week. With ad set budget sharing on, Meta's example allows up to 210% on a day and 8.4 times in a week.
What daily budget should I set for a monthly budget on Google Ads?
Divide the monthly budget by 30.4. A monthly budget of 3,040 is a daily budget of 100, and Google's monthly charging limit is then exactly 3,040.
Does Microsoft Advertising use 30.4 days too?
No. Microsoft's monthly budget limit is the daily budget times the actual number of days in the month, so a 100 daily budget allows 2,800 in February 2026 and 3,100 in a 31-day month.
Does TikTok ever spend more than the daily budget?
Not on a standard daily budget, which TikTok describes as the maximum per day. With Dynamic Daily Budget on, it may spend up to 25% more on a day, with the week capped at 7 times the daily budget.
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