How do I calculate CPM?

Divide total spend by impressions, then multiply by a thousand. CPM is the cost of reaching a thousand impressions, which is why the multiplication is there, it is a rate, not a total.

What is a good CPM or CPC?

There is no answer to that which is true across accounts, and this tool deliberately does not offer one. CPM depends on the objective, the audience size, the format, the season and who else is bidding for the same people on the same day. A festive-season CPM in India is not comparable to an off-peak one in the same account, let alone to another advertiser.

Why is my ROAS good but the campaign still loses money?

ROAS is revenue divided by ad spend, so it ignores your cost of goods, your fees and every other cost. A 4x ROAS on a product with a 20% gross margin is a loss. ROAS is a media efficiency measure, not a profitability measure.

Should I use link clicks or all clicks?

Link clicks, for anything you report. All clicks includes likes, comments, profile taps and expansions, which inflates CTR and deflates CPC without anyone visiting your site. Two agencies reporting the same campaign can differ by a factor of three purely on this choice.

Why do my numbers differ from the platform dashboard?

Usually attribution windows or a different click definition. Platforms count conversions inside their own window and will each claim the same sale. If your arithmetic here does not match the dashboard, check which click type and which window the dashboard is using before assuming either is wrong.

Ad metrics calculator (CPM, CPC, CTR, CPA, ROAS)

Turn campaign spend and results into CPM, CPC, CTR, CPA and ROAS, each with its arithmetic shown.

Free. No sign-up. Runs in your browser. Checked 2026-09-09.

Estimate from your inputs

CPM (cost per 1,000 impressions): Rs 40
CPC (cost per click): Rs 6
CTR (click-through rate): 0.7%
CPA (cost per acquisition): Rs 286
ROAS (return on ad spend): 4.8x

Amounts are in Indian rupee (INR), rounded to the nearest whole unit, and hours to one decimal place. Changing the currency changes the symbol only - nothing is converted. Everything comes only from the values you entered above. Method version 1.0, updated 2026-09-09.

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Ad metrics calculator (CPM, CPC, CTR, CPA, ROAS) - Estimate from your inputs
Method version 1.0, updated 2026-09-09
Amounts in Indian rupee (INR)

Your inputs
- Total ad spend: 50000
- Impressions: 1250000
- Clicks: 8750
- Conversions: 175
- Revenue attributed: 240000

Results
- CPM (cost per 1,000 impressions): Rs 40
  Rs 50,000 / 1250000 impressions x 1,000 = Rs 40
- CPC (cost per click): Rs 6
  Rs 50,000 / 8750 clicks = Rs 6
- CTR (click-through rate): 0.7%
  8750 clicks / 1250000 impressions x 100 = 0.7%
- CPA (cost per acquisition): Rs 286
  Rs 50,000 / 175 conversions = Rs 286
- ROAS (return on ad spend): 4.8x
  Rs 2,40,000 revenue / Rs 50,000 spend = 4.8x

What this estimate excludes
- Media spend only. Your management fee, creative production and tooling are not in these figures, so ROAS here is not agency profitability.
- Platform-attributed results. Every network claims conversions on its own attribution window, and two platforms will happily claim the same sale.
- No benchmark. What counts as a good CPM depends on the objective, the audience and the auction on the day - a number from another advertiser’s account cannot tell you whether yours is healthy.
- ROAS is revenue over spend, not profit. A 4x ROAS on a product with a 20% margin loses money.

Calculated at poststack.ai from the values above. These are estimates from
your own inputs, not measured results and not a benchmark.

How this works, what it excludes, and the FAQsShow

Who this is for

Agencies and freelancers running paid social for clients, and anyone checking a platform’s reported numbers against their own arithmetic before it goes into a report.

The formulas

CPM = spend ÷ impressions × 1,000

CPC = spend ÷ clicks

CTR = clicks ÷ impressions × 100

CPA = spend ÷ conversions

ROAS = revenue ÷ spend

Any metric whose denominator is missing is skipped rather than shown as zero. A cost per acquisition of “Rs 0” from zero conversions reads as free rather than undefined, and that is exactly the kind of number that ends up in a client deck unchallenged.

Which metric answers which question

CPM, what does attention cost?: The price of being seen. Rising CPM with stable performance usually means auction pressure, not a creative problem.
CTR, is the creative working?: The clearest signal of whether the ad earns a response. It is the first thing to look at when CPC rises.
CPC, what does a visit cost?: A product of CPM and CTR rather than an independent lever. You lower it by improving creative or finding cheaper inventory, not by adjusting it directly.
CPA, what does a customer cost?: The first metric that includes what happens after the click. A good CPC with a bad CPA points at the landing page, not the ad.
ROAS, did the media pay for itself?: Revenue per rupee of spend. Media efficiency only, it says nothing about margin or profit.

Why there is no benchmark here

Published CPM and CTR benchmarks are averages across advertisers, objectives, countries and years that have almost nothing to do with your account. A festive-season CPM in India is not comparable to an off-peak CPM in the same account, and a lead-generation CTR is not comparable to a traffic campaign.

The comparison worth making is your own account over time, with one variable changed at a time. That is a real signal. A number from someone else’s spreadsheet is not.

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Frequently asked questions

How do I calculate CPM?: Divide total spend by impressions, then multiply by a thousand. CPM is the cost of reaching a thousand impressions, which is why the multiplication is there, it is a rate, not a total.
What is a good CPM or CPC?: There is no answer to that which is true across accounts, and this tool deliberately does not offer one. CPM depends on the objective, the audience size, the format, the season and who else is bidding for the same people on the same day. A festive-season CPM in India is not comparable to an off-peak one in the same account, let alone to another advertiser.
Why is my ROAS good but the campaign still loses money?: ROAS is revenue divided by ad spend, so it ignores your cost of goods, your fees and every other cost. A 4x ROAS on a product with a 20% gross margin is a loss. ROAS is a media efficiency measure, not a profitability measure.
Should I use link clicks or all clicks?: Link clicks, for anything you report. All clicks includes likes, comments, profile taps and expansions, which inflates CTR and deflates CPC without anyone visiting your site. Two agencies reporting the same campaign can differ by a factor of three purely on this choice.
Why do my numbers differ from the platform dashboard?: Usually attribution windows or a different click definition. Platforms count conversions inside their own window and will each claim the same sale. If your arithmetic here does not match the dashboard, check which click type and which window the dashboard is using before assuming either is wrong.