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Ad budget calculator

Turn a budget into projected reach, clicks, conversions and ROAS — or solve the other way and find the spend a revenue target actually requires.

Campaign plan

$
$
%
%
$
2.5×

Projected revenue

$12,750

2.55× ROAS on $5,000 spend
Impressions
416.7K
Unique reach
166.7K
Clicks
5K
Conversions
150
CPC
$1
CPA
$33.33

2.55× projected ROAS

Comfortable headroom. At this CPA of $33.33 the constraint is usually audience size, not economics — watch frequency as you scale.

A plan, not a promise. Real campaigns see CPM rise as you push frequency and spend, so treat these as the optimistic case and build in headroom.

In short

How do you plan a social media ad budget?

Multiply through the funnel. Budget divided by CPM gives thousands of impressions; impressions times CTR gives clicks; clicks times conversion rate gives conversions; conversions times order value gives revenue.

Then run it backwards. If you need $50,000 of revenue, the same chain in reverse tells you the spend required — and often tells you the target is not reachable at your current conversion rate, which is far cheaper to learn now than in week three.

The formula

Forward projection

Impressions = Budget ÷ CPM × 1,000 Reach = Impressions ÷ Frequency Clicks = Impressions × CTR Conversions = Clicks × CVR Revenue = Conversions × AOV

Reverse mode solves the same chain for budget. Because revenue scales linearly with spend at fixed assumptions, that is a single division — not an iteration.
The direction that matters

Most plans start from the target, not the budget

Nearly every free ad budget calculator only runs forwards: put a budget in, see what comes out. That is the easy half, and it is rarely the question being asked.

In practice the number that arrives fixed is the target. Someone needs $50,000 of revenue from paid social this quarter and the job is to work out what that costs — and whether it is achievable at all. Running the chain backwards answers that in one step.

It also fails loudly, which is the useful part. If the required budget comes back absurd, the plan was never going to work, and the conversation should be about conversion rate or order value rather than about media.

Assumptions

Where projections go wrong

A model is only as good as its three assumptions, and they are not equally dangerous:

  • Conversion rate is the killer. It sits at the end of the chain so every error compounds. Use your measured landing-page rate, not your click-through rate, and not the figure from a case study.
  • CPM rises as you scale. The first $1,000 buys your cheapest, most responsive audience. The tenth does not. A plan built on your test CPM will overshoot at ten times the spend.
  • CTR decays with frequency. The same people seeing the same creative for the fourth time click less. Long campaigns need creative rotation built into the budget.

Build the plan on the pessimistic end of each range. A campaign that beats a conservative model is a good problem; one that misses an optimistic one costs you the budget for the next test.

Afterwards

Close the loop once it has run

Once the campaign has data, put the real numbers through the CPM, CPC and CPA calculator and compare against what you projected here. The gap between the two is the most valuable thing you will learn — it tells you which of your three assumptions to fix before the next plan.

FAQ

Common questions

How do I work out my social media ad budget?

Work in whichever direction you actually have a fixed number for. If the budget is set, multiply it out through CPM, CTR and conversion rate to see what it should produce. If the revenue target is set, divide backwards to find the spend required. This calculator does both — the second direction is the one most media plans need and most calculators do not offer.

What is frequency and why does it matter?

Frequency is the average number of times each person sees your ad. Impressions divided by frequency gives unique reach. It matters because a campaign showing one ad eight times to a small group performs very differently from one reaching eight times as many people once — same impressions, completely different outcome, and rising frequency also pushes your CPM up.

What CPM, CTR and conversion rate should I assume?

Use your own past campaigns on the same platform and audience wherever possible. Industry averages are a last resort — they blend wildly different businesses and will be wrong for you in a direction you cannot predict. If you have no history, run a small test budget first specifically to establish these three numbers.

Why is my projected ROAS so different from my actual?

Usually the conversion rate. It is the assumption people are most optimistic about, and it compounds — a projection using 3% when reality is 1.5% overstates revenue by half. Landing-page conversion, not click-through rate, is what belongs in that field.

Should I spend the same amount every day?

Even daily pacing is the sensible default for evergreen campaigns because it gives the platform a stable signal to optimise against. Front-load only when there is a real deadline — a launch, an event, a sale ending — and expect a higher CPM when you do, because you are compressing the same spend into less time.

How much should I budget as a percentage of revenue?

The commonly cited range is 5–15% of revenue for marketing overall, with paid social a slice of that. Treat it as a sanity check rather than a method. Building the number from unit economics — what a customer is worth, what you can afford to pay for one — gives a defensible answer; a percentage of revenue gives you a number you have to justify afterwards.