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CTR Calculator

See what share of ad impressions or pageviews turned into clicks, as a percent and a decimal.

Denominator class

Must be greater than zero. Clicks cannot exceed impressions.

Clear

Ad CTR

—

Clicks per 100 ad impressions

clicks ÷ impressions × 100

Enter clicks and impressions. An empty field is not zero.

Decimal
—

How the click rate is worked out

Clicks and one denominator go in. The share that turned into clicks comes out as a percent and as a decimal.

  1. Pick the denominator

    Ad impressions for clicks per ad shown, or pageviews for clicks per page viewed.

  2. Enter clicks

    Clicks for one period, from the report that holds the denominator.

  3. Enter the count

    Ad impressions or pageviews for the same dates. It must be above zero.

  4. Read both forms

    The readout shows the percent to four decimals and the decimal to six, with the formula underneath.

Multiplier from ratio to percent
100
Decimal places on the percent
4
Decimal places on the decimal
6
Denominator classes to choose from
2

What the readout shows

This click-through rate calculator gives every rate twice: as a percent for reports and as a decimal for formulas.

  • Ad CTR

    Clicks per 100 ad impressions. It tops out at 100%, since more clicks than impressions is rejected.

    clicks ÷ impressions × 100

  • Pageview CTR

    Clicks per 100 pageviews. A page can carry several ads, so this rate may pass 100%.

    clicks ÷ pageviews × 100

  • Decimal

    The same rate as a fraction of one, to six decimal places, for spreadsheets and formulas.

    0.3500% → 0.003500

  • Formula line

    The division written out, clicks ÷ count × 100 = percent, with your own counts in it.

  • Ratio check

    With ad impressions picked, more clicks than impressions stops the calculation and names the problem.

  • Message line

    A dash and one line of text while a field is empty or the count is zero.

Three ways to write one click rate

The worked example uses made-up counts for one ad unit over one week.

  1. Ad CTR

    42 clicks in 12,000 ad impressions is 0.0035 of them, shown as 0.3500% with four decimal places.

  2. Decimal

    The Decimal row holds the same rate with six places, 0.003500. Paste that where a formula expects a fraction.

  3. Pageview CTR

    The same 42 clicks over 4,000 pageviews reads 1.0500%. The two rates differ by the ad impressions per pageview, here 3.

  4. Clicks per thousand

    The decimal × 1,000 gives 3.5 clicks per 1,000 ad impressions, the step that connects CTR to CPM and RPM.

How CTR lines up with CPM, CPC and RPM

The click rate is what links a price per click to a price per 1,000 impressions. These identities hold when every number comes from the same report and dates.

CPM from CPC and CTR
CPM = CPC × CTR as a decimal × 1,000. A 0.80 CPC at 0.35% (0.0035) is a 2.80 CPM.
Impression RPM from CTR
Impression RPM = ad CTR as a decimal × revenue per click × 1,000. At 0.35% and 0.40 per click, that is 1.40.
Pageview CTR from ad CTR
Pageview CTR = ad CTR × ad impressions per pageview, when both use the same clicks. 0.35% × 3 = 1.05%.
Clicks needed for a target
Clicks = impressions × target CTR as a decimal. Reaching 0.5% on 12,000 impressions takes 60 clicks.
Points and percent change
A move from 0.30% to 0.36% is 0.06 percentage points, and a 20% rise relative to where it started.

Reading a result

The readout keeps one layout for both denominators. This one shows a finished ad CTR.

  1. Label

    Ad CTR with ad impressions picked, Pageview CTR with pageviews picked.

  2. Percent

    Four decimal places and a % sign. A dash while a field is empty, the count is 0 or the ratio is impossible.

  3. Unit line

    Clicks per 100 ad impressions, or clicks per 100 pageviews.

  4. Formula line

    Repeats your two counts with thousands separators, then × 100 and the percent, so the rate can be checked by hand. Before both counts are in, it shows the formula in words.

  5. Decimal row

    The same rate with six decimal places. It shows a dash whenever the percent does.

Result states

A rate appears once both counts are valid. Otherwise the readout shows a dash and one of these messages, worded as on the workbench.

Result What it means What to do next
Ad CTR
Clicks and ad impressions are numbers, impressions are above zero and clicks do not exceed them. The Decimal row shows the same rate as a fraction.
Compare it with the same unit in another period, taken from the same report.
Pageview CTR
The denominator is pageviews. Clicks may exceed pageviews when pages carry several ads, so rates over 100% are shown.
Switch to ad impressions for the rate per ad shown.
Enter clicks and impressions
One of the two counts is missing. The percent and the decimal both show a dash, and the message ends “An empty field is not zero.” With pageviews picked, it asks for clicks and pageviews.
Fill both fields from one report and one date range.
Clicks cannot exceed impressions
With ad impressions picked, more clicks than impressions is impossible, so no rate is shown and the clicks field is marked.
Check that clicks and impressions cover the same unit and dates, and that no click was counted twice.
Cannot compute: impressions must be greater than zero
The count is 0, so there is nothing to divide by. With pageviews picked, the message names pageviews.
Take the count from dates that had traffic.
Cannot compute with these numbers
The rate is too large to store. That takes pageviews picked and an absurd entry, such as 1e308 clicks over one pageview.
Look for a stray exponent in the clicks field.
Clicks must be a finite non-negative number
The entry holds a minus sign, a percent sign, a comma or text. Impressions and Pageviews get the same message under their own name.
Type counts as digits, such as 12000.

Where clicks and counts come from

The calculator reads only what you type. Clicks and the denominator should come from one report.

ClicksAd report
Ad clicks for the unit or site you are measuring, from the report that also holds the impressions.
Ad impressionsAd report
Ads shown in the same period and scope. Only ads that were served count; empty slots add nothing.
PageviewsAnalytics
Page loads for the same pages and dates. Use them when you want clicks per page viewed.
ScopeYour choice
Site-wide, one section or one ad unit. Clicks and the count must share the same scope.
Date rangeYour choice
The calculator has no dates. Match the days and the time zone of both numbers.

What moves a CTR

A click rate changes when clicks or the count change. These are common reasons one period differs from the next.

Placement
Moving a unit changes how often it is seen, and with it how often it is clicked.
Units per page
Extra units add impressions faster than clicks, so ad CTR can fall while pageview CTR rises.
Ad refresh
Refreshing a slot adds impressions without new pageviews, which lowers ad CTR unless clicks grow at the same pace.
Filtered clicks
If invalid clicks are removed after the period, a later report shows fewer clicks and a lower CTR.
Audience and device
Visitors on other devices or from other sources can click at different rates.
Denominator switch
Moving from ad impressions to pageviews changes the rate with no change on the site.

What to enter

Two counts from one report. Clicks may be 0; the denominator must be above 0.

Accepted

  • 42

    Whole clicks.

  • 2.5

    Fractional clicks, such as a daily average, are accepted.

  • 12000

    Impressions or pageviews as plain digits.

  • 0

    Zero clicks is a real result: 0.0000%.

Read as

  • 1.2e4becomes12,000

    Scientific notation is read in full, with separators in the formula line.

  • +42becomes42

    A leading plus sign is dropped, and spaces around the number are trimmed.

Not accepted

  • 0.35%

    The fields take counts. A percent sign makes the entry invalid.

  • 12,000

    A comma makes the entry invalid. Type 12000.

  • -3

    Counts cannot be negative.

  • 50 clicks, 40 impressions

    With ad impressions picked, this returns “Clicks cannot exceed impressions.” With pageviews picked, it is accepted.

Example click rates

Four cases with made-up counts. The readout wording is exact.

Weekly CTR for one unit

Clicks 18 · Ad impressions 7500
You see
Ad CTR 0.2400% and Decimal 0.002400.
What it means
2.4 clicks for every 1,000 times the ad was shown.
Next
Compare with the same unit's previous week, from the same report.

Clicks per page viewed

Clicks 310 · Pageviews 62000
You see
Pageview CTR 0.5000% and Decimal 0.005000.
What it means
One click for every 200 pageviews, across all the ads on those pages.
Next
Switch to ad impressions to see how each unit does.

A rate above 100%

Clicks 15 · Pageviews 10
You see
Pageview CTR 150.0000% and Decimal 1.500000.
What it means
Clicks outnumber pageviews, which the pageview class allows because a page can carry several ads.
Next
Check that the count covers the same pages as the clicks before reporting it.

More clicks than impressions

Clicks 50 · Ad impressions 40
You see
No rate. The readout says “Clicks cannot exceed impressions.”
What it means
An ad cannot be clicked more often than it was shown, so one of the two numbers is off.
Next
Check that both cover the same unit and dates.

Before you report a CTR

A click rate travels well only with its denominator and its dates attached.

  1. Name the denominator

    Write ad CTR or pageview CTR next to the figure. The two differ by the ad impressions per pageview.

  2. Same scope

    Clicks and the count should cover the same unit, section or site.

  3. Same dates

    Use whole days in one time zone for both numbers.

  4. Enough impressions

    On 300 impressions, one extra click moves the rate from 0.33% to 0.67%. Wait for more data before comparing.

  5. Percent or decimal

    Put the decimal in formulas and the percent in reports, so nobody multiplies by 100 twice.

  6. One change per test

    To calculate click-through rate for a creative or placement test, change one thing per period so the rate can be traced to it.

Questions that need more than two counts

A click rate is one division. These questions need earnings, spend, history or the network's own data.

Question Why the calculator cannot answer it Where to look
Is my CTR good?
The calculator holds no benchmark, and rates vary by format, placement and audience.
Your own earlier periods, measured the same way.
How much did those clicks earn?
CTR counts clicks. Revenue needs the earnings column of your report.
RPM Calculator turns revenue and a count into revenue per 1,000.
What did each click cost the advertiser?
A price per click needs the spend behind the clicks.
CPM Calculator adds CPC when you enter clicks.
Were the clicks valid?
Invalid-click filtering happens inside the ad network. The calculator counts what you enter.
Your ad network's reports and account notices.
Why did my CTR drop?
The calculator shows the rate for the numbers you enter. The cause sits in placement, traffic or filtering changes.
Runs from before and after each change, checked against what moves a CTR.

CTR Calculator and related tools

Clicks connect ad prices and ad revenue. Each of these tools takes a different slice.

CTR Calculator compared with related tools
CTR Calculator This tool CPM Calculator RPM Calculator AdSense Revenue Calculator
Answers What share of ad impressions or pageviews turned into clicks What 1,000 impressions cost, and the cost per click What 1,000 pageviews or ad impressions earned What pageviews could earn at a benchmark page RPM
Money involved None: counts only Spend Revenue A benchmark RPM
You enter Clicks and ad impressions or pageviews Cost, impressions and optional clicks Revenue and pageviews or ad impressions Monthly pageviews, a category and a region
Result CTR as a percent and a decimal CPM and CPC Page or impression RPM, and same-period revenue A monthly baseline and a yearly figure

Who works out click rates

Anyone with a click count and something to divide it by.

  • Site owners

    See whether a layout change moved clicks per pageview from one month to the next.

  • Ad operations teams

    Read ad CTR per unit after a placement test, from the unit report of the network.

  • Media buyers

    Put a campaign's click rate next to its CPM and CPC.

  • Analysts

    Turn dashboard percentages into decimals for models, and check a reported rate against its counts.

Words used on this page

Definitions for the readout and the examples.

CTR
Click-through rate: clicks ÷ impressions × 100, the share of impressions that led to a click.
Ad impression
One ad shown in a slot.
Pageview
One load of a page, whatever the number of ads on it.
Denominator class
What the clicks are divided by: ad impressions or pageviews. The result label names it.
Decimal form
The rate as a fraction of one: 0.35% is 0.0035.
Percentage point
The difference between two percents. 0.30% to 0.36% is 0.06 points.
Clicks per thousand
CTR as a decimal × 1,000. At 0.35%, 3.5 clicks per 1,000 impressions.
Impossible ratio
More clicks than ad impressions. The calculator rejects it.

Common questions

What is the CTR formula?

Clicks ÷ impressions × 100. For 27 clicks in 9,000 ad impressions: 27 ÷ 9,000 = 0.003, and × 100 gives 0.30%. That is how to calculate CTR by hand, and the formula line shows the same steps.

Why show a decimal as well as a percent?

Spreadsheets and bidding formulas expect the fraction, 0.003, while dashboards show 0.30%. Having both on screen stops anyone multiplying by 100 twice.

Should I divide by ad impressions or pageviews?

Ad impressions give clicks per ad shown, which suits comparing units. Pageviews give clicks per page viewed across all its ads, which suits comparing layouts. With ad impressions picked, the page works as an ad CTR calculator.

Why can pageview CTR go above 100%?

A page with several ads can collect more than one click per view. With pageviews picked, 15 clicks on 10 pageviews reads 150.0000%.

Why are more clicks than impressions rejected?

An ad cannot be clicked more times than it was shown. A ratio like that points to mixed dates, mixed units or double-counted clicks, so the calculator stops with “Clicks cannot exceed impressions.”

Why does 1 click in 3 show 33.3333%?

The percent is rounded to four decimal places and the decimal to six, so 1 in 3 reads 33.3333% and 0.333333. The decimal is worked out from the unrounded percent.

Does an empty clicks field mean zero clicks?

No. An empty field is missing data, so the readout waits with a dash. Type 0 for a period with no clicks and the rate reads 0.0000%.

Can I type a rate instead of counts?

The fields take counts, and a percent sign such as 0.35% makes the entry invalid. To get from a rate back to clicks, multiply impressions by the rate as a decimal.

Can I compare two ad units with it?

Yes, one run per unit. Give each unit its own clicks and its own ad impressions for the same dates, then compare the two percents. Shared site-wide clicks over one unit's impressions give a rate that belongs to neither.

Work out another click rate

Enter clicks and a count in the calculator above. The rate updates as you type.

Enter your counts