Google Ads budget calculator

Enter a monthly budget to get the average daily budget to set in Google Ads: divide by 30.4. On any single day Google can spend up to twice that, but for most campaigns you are never charged more than 30.4 times your average daily budget in a month. Or start from the leads you want and your cost per lead.

How does Google Ads spend a daily budget?

Google calls it an average daily budget: "the average amount that you set for each ad campaign on a per-day basis". Two limits apply:

• Daily spending limit: "two times your average daily budget for most campaigns".
• Monthly spending limit: "30.4 times your average daily budget for most campaigns", where 30.4 is the average number of days in a month (365 divided by 12).

Google says "you'll never actually pay more than your spending limits", and if served costs go over them, "Google will cover the difference".

Worked example: a £10 average daily budget can spend up to £20 on a busy day, and up to £304 in a month.

How much should you budget?

Work back from results:

1. Decide how many leads or sales a month you need.
2. Estimate your cost per lead from past data. With no history, Keyword Planner forecasts take "your bid, budget, seasonality, and historical ad quality into account".
3. Multiply, then divide by 30.4 for the daily budget.

Then check after two to four weeks: if a profitable campaign shows a high "Search lost IS (budget)", the budget is holding it back. See impression share lost to budget vs rank.

What about shared and total budgets?

• Shared budgets let several campaigns share one average daily budget. Google says they are "only available on Search, Shopping, Display, and Video campaigns".
• Campaign total budgets set one amount for a fixed period instead of a daily budget. Google says you "will never be charged more than your total budget", the minimum period is 3 days, and you "can't change the budget type after a campaign is created".

Questions

How do I convert a monthly Google Ads budget to daily?

Divide the monthly budget by 30.4. A £1,000 monthly budget is an average daily budget of about £32.89.

Why did Google spend more than my daily budget?

Google can spend up to twice your average daily budget on one day, but not more than 30.4 times it over the month.

What is the minimum Google Ads budget?

Google does not set one figure. The budget needs to buy enough clicks for your conversion rate to produce results you can judge.

Sources

All read on 22 October 2026, Google Ads Help:

• About average daily budgets: support.google.com/google-ads/answer/6385083
• Overdelivery: support.google.com/google-ads/answer/2375423
• Spending limits: support.google.com/google-ads/answer/10486637
• Shared budgets: support.google.com/google-ads/answer/10487241
• Campaign total budgets: support.google.com/google-ads/answer/10486938
• Keyword Planner forecasts: support.google.com/google-ads/answer/3022575

Related: Lost impression share: budget vs rank · Google Ads audit checklist · Nudge FAQ