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Ad Budget Calculator

Plan a campaign forward from budget, or backward from a conversion target. Every number on the page updates as you type.

Free toolsPaid MediaReviewed September 2026

Plan direction

Media cost for the period you are planning.

RatesThe three rates that turn budget into conversions, plus order value for revenue.

Cost per 1,000 impressions.

Clicks ÷ impressions.

Conversions ÷ clicks.

Optional. Revenue per conversion, for revenue and ROAS.

Conversions

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Forecast at these rates

Impressions
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Clicks
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CPC
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Budget ÷ clicks
CPA
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Budget ÷ conversions
Revenue
–
Needs order value
ROAS
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Needs order value

Runs entirely in your browser. Nothing you enter is stored or sent anywhere. Last reviewed September 2026.

Funnel

Stage Volume Rate Cost

A media plan is three rates and a budget

Every paid campaign is the same chain: money buys impressions, a share of impressions become clicks, a share of clicks become conversions. CPM, click-through rate, and conversion rate are the three links. Fix those and the budget determines the outcome, or the outcome determines the budget. This tool runs the chain in either direction so you can plan from what you have or from what you need.

The forward mode answers the question a finance partner asks: what does $10,000 get us? The backward mode answers the one a sales leader asks: what does it cost to deliver 250 leads? Both use the same arithmetic, and both are only as good as the rates you feed them. Pull those from recent history in the same channel and campaign type, not from a blended account average.

The main thing a linear model misses is that rates degrade as spend grows. The first dollars reach the most responsive audience; later dollars reach people who are less interested, so CTR and conversion rate fall and CPM often rises as you compete for the same inventory. Use the funnel table to see which rate carries the most leverage, then stress the plan by making that rate 25% worse before you commit to it.

Formulas

Forward: Impressions
= Budget ÷ CPM × 1,000
Forward: Clicks
= Impressions × CTR
Forward: Conversions
= Clicks × Conversion rate
Backward: Clicks
= Target conversions ÷ Conversion rate
Backward: Impressions
= Clicks ÷ CTR
Backward: Budget
= Impressions × CPM ÷ 1,000
CPC
= Budget ÷ Clicks
CPA
= Budget ÷ Conversions
Revenue
= Conversions × Average order value
ROAS
= Revenue ÷ Budget

Frequently asked questions

How do I forecast conversions from an ad budget?

Walk the budget down the funnel. Divide budget by CPM and multiply by 1,000 for impressions, multiply by click-through rate for clicks, then multiply by conversion rate for conversions. $10,000 at a $12 CPM buys about 833,000 impressions; at a 1% CTR that is about 8,300 clicks; at a 3% conversion rate that is 250 conversions, a $40 CPA. Change any rate and every number downstream moves with it.

How do I work out the budget needed for a conversion goal?

Run the same chain in reverse. Divide the conversion target by conversion rate to get the clicks required, divide clicks by CTR to get the impressions required, then multiply impressions by CPM and divide by 1,000 to get the budget. Switch the tool to backward mode and enter the target; it fills in the rest. The rates come from your own account history, and the model assumes they hold as spend scales, which they rarely do exactly.

Where should the CPM, CTR, and conversion rate come from?

From the same platform and campaign type you plan to run, over the most recent comparable period. Blended account averages hide big differences between prospecting and retargeting, search and social, mobile and desktop. If you have no history, use the platform planning tools for a CPM estimate and be conservative on CTR and conversion rate. Then treat the forecast as a range: run the tool at a rate 25% worse than you expect and make sure the plan survives that.

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