Google Ads budget calculator

Run the funnel backwards: from the conversions you want to the budget that buys them.

Runs entirely in your browser — nothing is uploaded, nothing is stored. Updated 2026-09-05.

The budget you need is target conversions ÷ conversion rate × cost per click. Wanting 60 conversions at a 3.2% conversion rate and a $3.85 CPC means 1,875 clicks and a budget of $7,219.

This runs the funnel backwards, which is the only sane way to set a Google Ads budget: pick the outcome, derive the spend, then check the implied cost per acquisition against what your margin can absorb. If that CPA is above your ceiling, the plan is wrong before a single ad runs — and no amount of optimisation inside the campaign will fix a plan that was never viable.

Do not plan from the account-average conversion rate

An account average blends branded search converting at 12% with generic terms converting at 1.5%. Plan a generic-term campaign on the blended figure and the budget will be short by a factor of three or four.

Use the conversion rate of the campaign type you are actually planning. If there is no history for it, plan on the lowest defensible rate you have and treat the first month as a measurement exercise rather than a performance one.

Check the implied CPA before you check anything else

The implied CPA the calculator returns is the plan's real test. Compare it against the ceiling your margin allows — average order value times gross margin, which the CAC calculator works out.

If the implied CPA is above that ceiling, no budget makes this plan work. What changes it is a higher conversion rate, a lower cost per click, or a higher order value — and those are product and creative problems, not budget ones.

The daily budget is a cap, not a rate

Google Ads treats a daily budget as an average, spending up to twice it on a high-demand day and settling over the month. A campaign set at $240 a day can spend $480 on a Tuesday and $60 on a Sunday without anything being wrong.

Judge pacing over a full month, and remember that a budget-limited campaign is losing impression share every day it caps out — which the plan above cannot see, because it assumed you could buy every click you needed at the price you assumed.

Computing this from your own accounts

Every calculator on this page takes numbers you typed. The version that keeps working is the one that reads them from the accounts themselves — which is what TableBI is: connect Google Ads, Meta Ads, GA4 or Search Console once, and cpa() becomes a macro you can query from your terminal.

# connect once, then the metric is a standing query
tablebi connect google_ads
tablebi connect meta_ads   # beta: your own or test ad accounts

tablebi ask "WITH w AS (SELECT MAX(date) AS anchor FROM metrics)
   SELECT platform, cpa(SUM(cost), SUM(conversions)) AS cpa
   FROM metrics, w WHERE date > w.anchor - 30
   GROUP BY platform ORDER BY cpa DESC"

# pin the answer to a URL that refreshes itself
tablebi pin --title "Google Ads budget calculator by channel"
→ https://you.tablebi.com/d/dsh_…

The pinned answer is a live URL that refreshes on its own — here is one running now. No hosted model does the reasoning; your own Claude Code or Codex drives the CLI, which is why there is no inference bill attached to it.

Questions people ask about google ads budget calculators

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