How much should you spend on ads?
Work backwards from the result you want. Decide how many sales or leads you need, then use your conversion rate and cost per click to find the budget that gets you there.
Ad budget formula
Budget = (goal ÷ conversion rate) × CPC
Example: 50 sales at a 2% conversion rate needs 2,500 clicks. At 0.80 per click, that is a 2,000 budget, or about 67 a day over 30 days.
Setting a daily budget on Meta and Google
Both platforms spend around your daily budget on average, so divide the total by the number of days. Start a little lower while the campaign learns, then scale what works. Check whether the cost per conversion is profitable with the break-even ROAS calculator.
Where to get your numbers
Use your own past conversion rate and CPC. If you have none, run a small test campaign first; guessing these two numbers is the most common reason budgets miss.
Ad spend calculator: work backwards from your goal
Clicks needed = goal ÷ conversion rate
Ad budget = clicks needed × CPC
Example: you want 50 sales, your site converts 2% of visitors and clicks cost $0.80. You need 50 ÷ 0.02 = 2,500 clicks, so the budget is 2,500 × $0.80 = $2,000, or about $67 a day over 30 days.
Ad budget calculator for Meta (Facebook and Instagram)
Meta's delivery system needs data to learn. Give each ad set enough budget to get several conversions a week; if your daily budget only buys a handful of clicks, results will swing wildly from day to day. Start with the daily budget this calculator suggests, run it for at least a week, then replace the guesses with your real CPC and conversion rate.
Advertising budget vs marketing budget
Your marketing budget covers everything: ads, content, tools, people and agencies. The advertising budget is just the paid media part. Once ads are running, check they pay off with the ROAS calculator and the break-even ROAS calculator.
Ad budget in India and other lower-cost markets
Clicks and impressions often cost less in markets such as India, so the same goal can need a smaller budget. The formula is the same everywhere: enter local CPC and conversion rates and the calculator works in any currency, as long as you use one currency throughout.
How to use this calculator
Enter conversions you want, conversion rate, cost per click and campaign length. The result updates as you type, so you do not need to press Calculate after each change. Use Copy result to paste the figure into a report, or Share link to send the calculator with your numbers already filled in.
Related calculators
You may also want the CTR Calculator (Click-Through Rate), Email CTR and Click-to-Open Rate Calculator, CPM Calculator. Browse everything in ad cost metrics calculators.
Frequently asked questions
What if I don't know my conversion rate?
Run a small test, or use a cautious guess and update the plan after a week of data.
Does this work for leads?
Yes. Use leads as your goal and your lead conversion rate.
How much should a small business spend on ads?
Start with what a single customer is worth to you. Work out the budget needed for a modest goal with this calculator, test for a few weeks, and scale only if the return covers the cost.
Results are estimates based on the numbers you enter and are not financial advice.