What is the formula for reach from budget?

First compute impressions = (Budget / CPM) × 1,000. Then estimate reach = impressions ÷ frequency.

Is reach the same as impressions?

No. Impressions are total ad views. Reach is an estimate of unique people/accounts. A common approximation is impressions = reach × frequency.

What does frequency mean here?

Frequency is the average number of impressions per reached person/account. It's an assumption that affects reach materially.

Why is this only an estimate?

Actual reach depends on platform reporting, audience overlap, targeting, delivery, and how frequency is distributed (not uniform).

What CPM should I use?

Use your historical CPM for the same channel/geo/targeting, or a conservative planning value. CPM can vary by seasonality and inventory quality.

Media Planning Tool

CPM Reach Calculator

Estimate how many people you can reach from a budget, CPM, and average frequency. Or work backwards from a target reach to the required budget.

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Reach estimator

Convert between budget and reach using CPM and average frequency.

100% FreeTwo-way

Reach is an estimate of unique people/accounts. Impressions = reach × frequency. Frequency is an assumption—small changes can shift reach materially.

Example presets

Budget (USD)

CPM (USD)

Average frequency

Estimated reach

Formula: Reach = (Budget / CPM) × 1,000 ÷ Frequency

Impressions

500,000

Reach

250,000

Assumptions: CPM US$10.00, average frequency 2.

What you get

Two-way calculator

Estimate reach from budget, or budget from a target reach.

Frequency-aware

Reach is derived from impressions ÷ frequency, so the assumption is explicit.

Fast presets

Start with common examples, then adjust to your channel and audience.

Clear definitions

Avoid mixing up reach and impressions with plain-language guidance.

How it works

Pick your direction

Choose whether you're estimating reach from budget or budget from reach.

Enter CPM and frequency

Add your CPM assumption and an average frequency for the campaign.

Read the result

Review estimated reach, implied impressions, and formulas.

FAQ

Plan reach in seconds

Sanity-check reach and budget assumptions before you buy.

Start calculating

This tool provides planning estimates only. Actual reach depends on platform definitions, audience overlap, targeting, and delivery conditions.