How do you calculate CTR?

Divide the clicks by the impressions and multiply by one hundred. 100 clicks from 10,000 impressions is 100 / 10,000 x 100, which is 1.00%, or one click in every 100 impressions. The page prints that substituted division under the figure, so the number can be checked rather than trusted, and it prints the plain fraction beside a rate that does not terminate: 1 click of 3 impressions is 33.33%, shown to two decimal places, with 1 / 3 written next to it.

How many clicks is a given rate worth, and how many impressions do I need?

Switch Solving to Clicks and the page multiplies instead of dividing: 2.5% over 50,000 impressions is 1,250 clicks. Switch it to Impressions and it works the other way: 100 clicks at a 1% rate needs 10,000 impressions. Where a rate does not land on a whole number of clicks, it says so in the working rather than rounding in silence, because a rounded count would be a different rate from the one you typed.

Why does it refuse clicks above impressions instead of showing the rate?

Because there is no such rate. A click-through rate is the share of impressions that were clicked, so it cannot pass 100%, and 12,000 clicks from 10,000 impressions is not a 120% campaign: it is two columns the wrong way round, or two different date ranges. The page names both numbers back to you and says to check the order, which is the fix in almost every case. What you typed stays in the boxes while you fix it.

What is the difference between percentage points and percent here?

Subtracting one rate from another gives percentage points. Campaign A at 1.00% against campaign B at 1.50% is a gap of 0.50 points, and at 12,000 impressions that gap is worth 60 clicks: the same 12,000 impressions at 1.00% would have produced 120 clicks, where B had 180. Dividing one rate by the other is a different quantity with a different meaning, and this page does not report it, because the two are constantly mistaken for each other.

This page does not say, and that is on purpose. A rate only means something next to the placement, the audience and the format it came from, so a single number published as a target would be wrong for most of the people reading it. What you get here is the arithmetic: the rate, the division that produced it, and the gap between two of your own campaigns in percentage points, which is a comparison that holds because both sides of it are yours.

Do my numbers leave the browser?

No. The division happens in the page itself, with no upload, no account and no sign-up. What you last typed is kept in this browser so the page opens where you left it, and the Start over button at the top of the page forgets it. The site counts that this tool was opened and nothing else: not your clicks, not your impressions, and not any figure on the page.

CTR Calculator

Click-through rate is one division: clicks divided by impressions, times one hundred. This page does that division and writes the substituted arithmetic beside the answer, so 100 clicks from 10,000 impressions reads 1.00% with 100 / 10,000 x 100 under it, and one click in every 100 impressions spelled out. Enter any two of the three numbers and it solves the third, so 2.5% over 50,000 impressions comes back as 1,250 clicks. Clicks above impressions are refused by name rather than shown as a rate above 100%, because that input is almost always two columns the wrong way round. A second campaign can be set beside the first: the gap is subtracted in percentage points, never dressed up as a percentage change, and then turned back into clicks. No account, nothing gated, and the numbers stay in your browser.

CTR1.00%100 clicks · 10,000 impressions · clicks / impressions x 100

CTR

1.00%

Clicks

Impressions

Solving

100 / 10,000 x 100 = 1.00%. That is one click in every 100 impressions.

Click-through rate (solved)100 / 10,000 x 100 = 1.00%
1.00%
Clicksas entered
100
Impressionsas entered
10,000

Compare a second campaign

Campaign A is the one above. Fill both boxes to see the gap in percentage points and what that gap is worth in clicks. Leave them empty and nothing is compared.

Campaign B clicks

Campaign B impressions

Points, not percent. Subtracting one rate from another gives percentage points: 1.50% against 1.00% is a gap of 0.50 points. Dividing one rate by the other gives a relative difference instead, and for the same pair of campaigns those two answers are different sizes, which is where most of the confusion around this number lives. This page subtracts, says points, and turns the gap back into clicks over the same impressions. It computes the stated formula and carries no benchmark, target or advice about what any rate is worth.

Common questions

How do you calculate CTR?: Divide the clicks by the impressions and multiply by one hundred. 100 clicks from 10,000 impressions is 100 / 10,000 x 100, which is 1.00%, or one click in every 100 impressions. The page prints that substituted division under the figure, so the number can be checked rather than trusted, and it prints the plain fraction beside a rate that does not terminate: 1 click of 3 impressions is 33.33%, shown to two decimal places, with 1 / 3 written next to it.
How many clicks is a given rate worth, and how many impressions do I need?: Switch Solving to Clicks and the page multiplies instead of dividing: 2.5% over 50,000 impressions is 1,250 clicks. Switch it to Impressions and it works the other way: 100 clicks at a 1% rate needs 10,000 impressions. Where a rate does not land on a whole number of clicks, it says so in the working rather than rounding in silence, because a rounded count would be a different rate from the one you typed.
Why does it refuse clicks above impressions instead of showing the rate?: Because there is no such rate. A click-through rate is the share of impressions that were clicked, so it cannot pass 100%, and 12,000 clicks from 10,000 impressions is not a 120% campaign: it is two columns the wrong way round, or two different date ranges. The page names both numbers back to you and says to check the order, which is the fix in almost every case. What you typed stays in the boxes while you fix it.
What is the difference between percentage points and percent here?: Subtracting one rate from another gives percentage points. Campaign A at 1.00% against campaign B at 1.50% is a gap of 0.50 points, and at 12,000 impressions that gap is worth 60 clicks: the same 12,000 impressions at 1.00% would have produced 120 clicks, where B had 180. Dividing one rate by the other is a different quantity with a different meaning, and this page does not report it, because the two are constantly mistaken for each other.
What is a good CTR?: This page does not say, and that is on purpose. A rate only means something next to the placement, the audience and the format it came from, so a single number published as a target would be wrong for most of the people reading it. What you get here is the arithmetic: the rate, the division that produced it, and the gap between two of your own campaigns in percentage points, which is a comparison that holds because both sides of it are yours.
Do my numbers leave the browser?: No. The division happens in the page itself, with no upload, no account and no sign-up. What you last typed is kept in this browser so the page opens where you left it, and the Start over button at the top of the page forgets it. The site counts that this tool was opened and nothing else: not your clicks, not your impressions, and not any figure on the page.

Exact arithmetic: click-through rate is clicks divided by impressions, times one hundred. Enter any two and the third is solved, and a comparison subtracts one rate from the other in percentage points rather than calling it a percentage change. It computes the stated formula and carries no benchmark, target or advice.