Free calculator
Google Ads Budget Calculator From CPC and Conversion Rate
Enter your average CPC, your conversion rate and the sales or leads you need each month. You get the clicks that takes, the monthly budget, the average daily budget to set in Google Ads (the monthly figure divided by 30.4) and the cost per conversion the numbers imply, checked against your target. Nothing you type leaves your browser.
Calculator
Calculate Your Google Ads Budget
The form holds a worked example: a $4.50 average CPC, a 3% conversion rate, 60 conversions a month and a $160 target cost per conversion. Replace it with your numbers; the results update as you type.
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The math
How the Budget Math Works
A Google Ads budget is three numbers multiplied: the conversions you need, the clicks each one takes, and the price of a click. At a 3% conversion rate one sale takes 33.3 clicks (1 ÷ 0.03), so 60 sales take 2,000 clicks; at $4.50 a click that is $9,000 a month.
The same numbers give the cost per conversion before a dollar is spent: CPC ÷ conversion rate, or $4.50 ÷ 0.03 = $150. If that figure is above what a sale or lead is worth to you, a larger budget buys more of the same loss, which is why the calculator checks it against the target you enter.
Google asks for an average daily budget, not a monthly one. Divide the monthly figure by 30.4, the average number of days in a month (365 ÷ 12) and the figure Google's own Help page uses: $9,000 ÷ 30.4 = $296.05.
Used backwards the page is a CPC calculator: target cost per conversion × conversion rate is the most you can pay for a click, $160 × 0.03 = $4.80. It is also a Google Ads cost calculator for the planning side only; the return side, with margin and fee, lives in the ROAS calculator, and our guide on how much Google Ads costs covers what moves the CPC itself.
conversions ÷ conversion rate60 ÷ 0.03 = 2,000clicks × average CPC2,000 × $4.50 = $9,000.00monthly budget ÷ 30.4$9,000 ÷ 30.4 = $296.05CPC ÷ conversion rate$4.50 ÷ 0.03 = $150.00target cost per conversion × conversion rate$160 × 0.03 = $4.80Your inputs
Where to Find Your CPC and Conversion Rate
The calculator is only as good as the two rates you feed it. Take both from the same account and the same 90 days where you can.
CPC from an account that already runs
Use the Avg. CPC column over the last 90 days, at the campaign or ad group you are budgeting for. The search terms report splits it further: the queries that convert rarely cost the same as the ones that do not, and the converting price is the one to budget on.
CPC for a new account: Keyword Planner
With no history, Keyword Planner shows a top of page bid range, a low and a high figure, for each keyword in the location you choose. Budget on the high end until the account has its own data.
Conversion rate
Conversions ÷ clicks over the same window, from the Conv. rate column, counting only the action you are budgeting for: a sale or a qualified lead, never a page view. With no history, take the landing page's rate from another channel, or run the table below at 2%, 3% and 4% and budget for the lowest.
By conversion rate
Monthly Budget by Conversion Rate
Same $4.50 CPC and 60 conversions a month. Only the conversion rate moves.
| Conversion rate | Clicks needed | Monthly budget | Average daily budget | Cost per conversion |
|---|---|---|---|---|
| 2% | 3,000 | $13,500.00 | $444.08 | $225.00 |
| 3% | 2,000 | $9,000.00 | $296.05 | $150.00 |
| 4% | 1,500 | $6,750.00 | $222.04 | $112.50 |
| 6% | 1,000 | $4,500.00 | $148.03 | $75.00 |
Why conversion rate decides the budget more than CPC. Moving from 2% to 4% halves the budget, from $13,500 to $6,750, and halves the cost per conversion with it. A CPC cut of the same size, $4.50 to $2.25, is not yours to make: the auction sets the price and you can only nudge it with Quality Score and bids. The landing page, the offer and the match types are yours. In the example one extra point of conversion rate, 3% to 4%, saves $2,250 a month; a dime off the CPC saves $200.
Google's rules
The 30.4 Rule and the 2x Day Rule
Two limits from Google Ads Help that decide what a daily budget bills, and the case with no keywords.
The 30.4 rule
Google Ads Help works the average daily budget out as the monthly amount divided by 30.4, the average number of days in a month (365 ÷ 12), and sets the monthly spending limit at 30.4 times the daily budget for most campaigns. A $296.05 daily budget can bill $9,000 in a calendar month. An ad schedule does not shrink it: the campaign still paces to 30.4 times the daily budget however many days it is scheduled to run.
The 2x day rule
For most campaigns the daily spending limit is two times the average daily budget. On a busy day the $296.05 campaign can bill up to $592.11, and on a quiet one less, so that the average over the month matches the budget you set. Google's spending limits page states that you never pay more than either limit; when served costs run over, Google covers the difference. Judge the month, not the day.
Shopping and Performance Max
Shopping and Performance Max campaigns have no keywords, so Keyword Planner has no CPC for them. Budget from product-level data instead: the average CPC and conversion rate of the Shopping campaign or product group that already runs, or the Performance Max campaign's own cost and conversion columns. A new feed starts with a test budget and reads its real numbers after 30 days; our Google Ads for online stores page covers the structure.
Too expensive
When the Budget Is More Than You Have
Four moves that bring the number down without starving the campaign.
The math says $9,000 and you have $4,500
A campaign planned for 60 conversions and funded for 30 runs out of budget partway through the day; the clicks it does buy still cost $150 a conversion.
Plan for fewer conversions
Cut the goal, not the daily budget. 30 conversions at the same CPC and rate need 1,000 clicks and $4,500, or $148.03 a day, and the campaign shows all day. Add conversions back as the budget grows.
Broad match buys clicks that do not convert
Every click on a query that cannot become a sale or lead lowers the conversion rate and raises the budget.
Tighten match types and negatives
Phrase and exact match keep the clicks on the queries you planned for, and a negative keyword list blocks the rest. Fewer wasted clicks lifts the conversion rate, which cuts the budget at the same CPC.
The landing page converts 1.5%
At 1.5% the example needs 4,000 clicks and $18,000 a month for the same 60 conversions, double the budget at 3%.
Fix the page before the bids
Match the page headline to the ad, put one form or one phone number above the fold, and time the load on a phone. Each point of conversion rate the page gains takes $2,250 off the monthly figure in this example.
Five campaigns share one small budget
Each gets a fifth of the clicks, none reaches enough conversions to learn from, and the account cannot tell which one works.
Start with one campaign
One Search campaign on the keywords that already convert, with the whole budget, reaches its numbers first. Add the second once the first holds its cost per conversion for 30 days. Our Google Ads management page describes how we stage it.
Common mistakes
Where Google Ads Budget Math Goes Wrong
Six habits that make a PPC budget look smaller on paper than it is in the account.
- Daily budget set to monthly ÷ 30. The month can then bill 30.4 × $300 = $9,120 against a $9,000 plan. Divide by 30.4, the figure Google's own page uses.
- CPC taken from a published industry average. Averages blend every market, device and match type. Take the CPC from your account, or from Keyword Planner's range for your location.
- Conversion rate counted from every conversion action. Page views, scroll events and phone-number clicks in the Conversions column make the rate look higher and the budget smaller than reality. Count the one action you are buying.
- One day's spend read as the budget. Google can bill up to two times the daily budget on a single day. Judge the campaign on the month.
- Budget cut when cost per conversion is the problem. At $150 per conversion against a $120 target, a smaller budget buys fewer of the same overpriced conversions. Lower the CPC or lift the conversion rate, then set the budget.
- No target cost per conversion. Without a target every budget looks affordable. For a store, the ROAS calculator gives the target from margin; for leads, the cost per lead calculator gives it from close rate and job value.
How do I calculate a Google Ads budget?
Divide the conversions you need by your conversion rate to get the clicks it takes, then multiply the clicks by your average CPC. 60 conversions at a 3% conversion rate need 2,000 clicks; at $4.50 a click that is $9,000 a month, or $296.05 a day once you divide by 30.4. The calculator above runs these steps and checks the result against your target cost per conversion.
How much should I spend on Google Ads?
Enough to buy the clicks your conversion goal needs, at a cost per conversion you can afford. Work out the cost per conversion first: CPC ÷ conversion rate, $4.50 ÷ 0.03 = $150. If that fits what a sale or lead is worth, the budget is that figure times the conversions you want. If it does not fit, a bigger or smaller budget changes nothing; lower the CPC or lift the conversion rate before spending.
Why does Google ask for a daily budget, and how do I set it from a monthly amount?
Google Ads campaigns run on an average daily budget. Google Ads Help works it out by dividing the monthly amount by 30.4, the average number of days in a month (365 ÷ 12): $9,000 ÷ 30.4 = $296.05. The same page states that you never pay more than 30.4 times the average daily budget in a month, so the daily figure and the monthly figure describe the same spend.
Can Google Ads spend more than my daily budget in a day?
Yes. Google Ads Help states that for most campaigns the daily spending limit is two times the average daily budget, so a campaign set to $296.05 can bill up to $592.11 on a busy day. Over the month the average comes back to the daily budget, and the monthly spending limit of 30.4 times the daily budget still holds.
Where do I find my CPC and conversion rate?
In an account that already runs, use the Avg. CPC and Conv. rate columns over the last 90 days for the campaign you are budgeting, and the search terms report to see what the converting queries cost. For a new account, Keyword Planner shows a low and a high top of page bid for each keyword in your location; budget on the high end until the account has its own data.
Does the budget calculator work for Shopping and Performance Max?
The math is the same, but there are no keywords, so Keyword Planner cannot supply the CPC. Take the average CPC and conversion rate from the Shopping campaign or product group that already runs, or from the Performance Max campaign's own cost and conversion columns, and enter those. A new feed with no history starts with a test budget and gets its real numbers after the first 30 days.
Does the calculator store my numbers?
No. The math runs in your browser, and nothing you type is sent to us or saved anywhere.
Free audit
Want Us to Check the Account Behind the Budget?
Send us the account and the numbers you entered. We tell you whether we found what is driving the CPC up or holding the conversion rate down, and name one or two issues before any work starts.
- Google Partner agency
- Shopify Partner
- No obligation
Sources
Sources and Related Pages
- Google Ads Help, About average daily budgets: support.google.com/google-ads/answer/6385083. Average daily budget = monthly amount ÷ 30.4 (365 ÷ 12); for most campaigns you never pay more than two times the average daily budget on a day or 30.4 times it in a month. Read October 25, 2026.
- Google Ads Help, About spending limits: support.google.com/google-ads/answer/10486637. Daily spending limit = average daily budget × 2 for most campaigns; monthly spending limit = average daily budget × 30.4; with an ad schedule the monthly limit stays 30.4 times the daily budget. Read October 25, 2026.
- Logical Gecko, How Much Does Google Ads Cost? 2026 Price Guide.
- Logical Gecko, Google Ads Match Types: Broad vs Phrase vs Exact.
- Logical Gecko, Negative Keywords in Google Ads: A Practical 2026 Guide.