CPC, CPM, CTR, CPA and ROAS Explained: The PPC Metrics That Actually Matter

Open Meta Ads Manager or Google Ads and you are hit with a wall of abbreviations: CPC, CPM, CTR, CVR, CPA, ROAS. Each one tells you something different - and looking at the wrong one is how many brands make bad decisions with good intentions, even at lakhs a month in spend.

This guide explains every important metric in plain language, gives you the formula, and shows how they connect so you can find exactly where a campaign is leaking money.

CPM: cost per thousand impressions

CPM is what you pay for your ad to be shown 1,000 times. It reflects competition in the auction - CPMs usually rise during festive and peak seasons like Diwali, Black Friday or Christmas, when more brands advertise. On Meta, a poorly-engaging ad can also raise your CPM.

CTR: click-through rate

CTR shows how many people who saw your ad clicked it. It is your best signal of creative and message quality. On Meta, look at link CTR rather than "CTR (all)", which also counts likes and profile clicks.

CPC: cost per click

CPC is the average price of one click. On Google Search it depends on keyword competition and ad quality. On Meta it is mostly the result of CPM and CTR - a better CTR lowers your CPC even if CPM stays the same.

Conversion rate (CVR)

Conversion rate tells you what share of clicks became a sale or lead. If CTR is healthy but conversion rate is low, the problem is usually after the click - slow page, unclear price, weak offer or a confusing checkout.

CPA / CPL: cost per acquisition or lead

How to calculate and read CPA

What CPA tells you

CPA is what you pay to get one customer (or CPL for one lead).

Worked example: CPA against a ₹400 break-even

This is the number to compare with your break-even: if one customer brings ₹400 of profit before ads, a CPA above ₹400 loses money.

ROAS: return on ad spend

A 3x ROAS means ₹3 of revenue for every ₹1 spent. But revenue is not profit - read why a 3x ROAS can still lose money and work out your break-even ROAS before you celebrate.

How the metrics connect: the diagnosis chain

The metrics are links in one chain. When results are bad, walk down the chain and find the weakest link:

Ad metrics calculator

Enter your campaign numbers to calculate every metric at once. The example figures are a ₹10 lakh month. It runs in your browser - nothing is saved.

Other metrics worth knowing

Frequency (Meta)

Average number of times each person saw your ad. Rising frequency with falling CTR is the classic sign of creative fatigue.

Impression share (Google)

The share of eligible searches where your ad actually showed. Low impression share lost to budget means you could get more conversions with more budget; lost to rank means you need better ads or bids.

AOV (average order value)

Revenue ÷ orders. Raising AOV with bundles or upsells lets you afford a higher CPA.

Vanity metrics to stop worrying about

Likes, reach, followers and "CTR (all)" feel good but rarely predict sales. For a sales budget, judge campaigns by CPA and ROAS against break-even.

A simple weekly routine

Every Monday: check spend and CPA by campaign, then walk the chain (CPM → CTR → CVR) for anything above break-even, and fix one link at a time.

PPC metrics: frequently asked questions