What CTA and CTR mean and how they differ: the CTR formula, a cost-per-click example in baht (invented numbers), how to write a CTA, and 30 ready CTA lines for posts, captions and LINE OA.
CTA stands for Call to Action: the text or button that tells the reader what to do next, such as order, message us or add on LINE. CTR stands for Click-Through Rate, found by dividing clicks by the number of times people saw something. The two are linked: the CTA is what you write, the CTR is the number showing how many people acted on it. This article gives the formula, a baht example, and 30 CTA lines you can copy.
Key takeaways
- A CTA is text or a button that invites the next step; keep to one per piece
- CTR = clicks / impressions x 100, as a percentage
- A CTA is what you write, CTR is what you measure, and buying after the click is conversion rate
- There is no fixed good CTR; compare with your own shop's history
What is a CTA
A CTA (Call to Action) is an invitation to do one thing after reading or watching. It can be a button on a web page, the last line of a caption, or a message sent in a LINE OA, for example "Order at the link in bio" or "Message us for prices".
A good CTA makes the next step obvious. Without one, readers finish and scroll past without knowing what the shop wanted them to do.
A button on a web page or shop page, such as Add to cart
A closing line on a post or clip, such as Message us to reserve
A message in a LINE OA, such as Tap to see the menu
Text in a banner or ad, such as See all promotions
CTA and CTR are two of the online marketing terms you meet often. See the overview of all terms in What Digital Marketing Is.
What is CTR and how to calculate it
CTR (Click-Through Rate) is the click rate: of the people who saw a post, ad or link, what percentage clicked. Google Ads' help page says CTR is the number of clicks an ad receives divided by the number of times the ad is shown, and gives the example of 5 clicks on 100 impressions as a 5% CTR. Last checked Oct 2026.
CTR formula
Platforms may count "clicks" and "views" differently, for instance link clicks only, or every tap on an ad. Before comparing numbers across platforms, check what each one counts.
Example: CTR and cost per click in baht
An invented example. A made-up bakery called Rainy Day Bakery boosts a post with a 400 baht budget. Every number is invented to explain the formula; none of it is a real shop's result or a market average.
Invented example: change the CTA, read the result
Scroll the table sideways to see the remaining columns
The working: the old CTR is 60 divided by 2,000, times 100, which is 3.0%. Cost per click is 400 divided by 60, about 6.67 baht. With clicks up to 90 on the same budget, CTR is 4.5% and cost per click falls to about 4.44 baht.
WarningMore clicks is not more sales
More clicks do not mean sales will rise by the same amount. Look at how many people message or order after the click, which is measured by conversion rate. A real test changes one thing at a time. The example above is invented only to show the formula.
How CTA and CTR differ
People mix them up because both live in the same job, but they are different things. The table compares them with the next term in the chain, conversion rate.
CTA, CTR and conversion rate
Scroll the table sideways to see the remaining columns
If CTR is low, fix what people see before clicking: the image, headline and CTA. If CTR is fine but nobody buys, look at the landing page and price instead of rewriting the CTA again. This order is a general way to diagnose the problem.
What CTR counts as good
The honest answer is that no single number works for everyone. CTR depends on the platform, ad format, audience and product. Averages quoted in articles come from different datasets and should not be used to judge your shop.
A more useful method is to keep the CTR of your own posts or ads and compare with the previous ones. If a new piece beats your usual level, the direction is good. How to read account numbers is in reading Instagram Insights to plan the next post.
A click that does not turn into a purchase is a different number, the conversion rate, explained in What Conversion Rate Is.
How to write a CTA people click
CTAs that get clicks usually follow a few simple rules. Nothing complicated is needed.
Start with a verb, such as order, message, add, save
Say what they get after tapping, such as see the price list
One piece, one action; do not ask for three things at once
Keep the step short: one link, one button
Place it where the reader has finished the point, not mid-story
Do
Order your first cookie box at the link in bio
Message us to get the price list
Use words your customers really say
Don't
Click here, with no hint of what they get
Order, message and share in one sentence
Say only a few left when stock is plentiful
Caption ideas and message formulas that lead into a CTA are in sales caption formulas, and how to open a clip so viewers stay until the CTA at the end is in hooks for the first 3 seconds.
30 CTA lines for posts and LINE OA
The lines below come in 6 groups. Copy one and edit the fields in curly braces {} to fit your shop. Use one line per post.
Ordering, 5 lines
For inviting customers to ask before they decide; good for products that need choosing or custom work.
Messaging, 5 lines
For bringing customers into your LINE OA and closing chat messages.
LINE OA, 5 lines
For posts that do not need an immediate sale but should keep people around.
Follow and save, 5 lines
For promotion periods; include only conditions that are true.
Promotions, 5 lines
For customers who have received their order; collects reviews and repeat orders.
After purchase, 5 lines
WarningOnly say what is true
Lines with dates, limited quantities or discounts may be used only when they are true for your shop. Never say stock is low when it is plentiful. Customers notice quickly, and some claims can break a platform's advertising rules.
For greeting messages and auto-reply menus in LINE OA that need chained CTAs, see the full examples in LINE OA greeting message examples.
Test which CTA works better
Pick a piece with a fair number of views
If very few people see it the numbers swing too much to read. Test on a post or ad seen by hundreds or more.
Change the CTA only
Keep the image and content, change just the CTA line so you know what caused the result.
Give both the same time and budget
Compare pieces posted in a similar period with a similar budget.
Write results in a table
Record impressions, clicks, CTR, cost per click, and messages or orders.
Keep the winner and test the next thing
Test one more variable next round. Never change several at once.
Check before you post
Done 0/5
If a shop's account is new and you want the follower or like count not to look empty when customers visit, Instafollow's service is one option. It does not guarantee CTR, clicks or sales; results depend mainly on your content and CTA. See Instagram followers service or the free trial, available only for services open to trial.
ArticleLINE OA Greeting Message: Setup and 30 ExamplesA LINE OA greeting message is the text sent automatically when someone adds your account. Set it up step by step from the official LINE for Business guide, with a 4-part formula and 30 copy-ready examples by business type.For caption formulas that lead into a CTA
Article12 Sales Caption Formulas for Online Shops, With Fill-in-the-Blank Thai ExamplesTwelve fill-in-the-blank caption formulas for online sellers, each with a finished example, plus a closing-line bank and a pre-post checklist.And the service for your shop's Instagram account
ServiceBuy Instagram Followers, Likes & Reels ViewsGrow your Instagram with followers, likes, Reels views and comments. See the price per 1,000 up front, pay by PromptPay, and never share your password.CTA and CTR questions
What is a CTA
CTA is short for Call to Action: text or a button that invites the next step, such as order, message, add on LINE or follow.
What is CTR
CTR is short for Click-Through Rate: the click rate, calculated as clicks divided by impressions, times 100, as a percentage.
How do CTA and CTR differ
A CTA is what you write to invite action. CTR is the number measuring how many people clicked. A good CTA often helps CTR, but CTR also depends on the image and headline.
What should a good CTR be
There is no fixed number. It depends on the platform, format and audience. Comparing with your own shop's usual level reads better than averages from elsewhere.
How many CTAs per post
One per post where you can. Asking for several things at once leaves people unsure where to start.
Why is CTR high but nothing sells
Usually it is after the click: a slow landing page, an unclear price, or something that does not match the ad. Look at conversion rate and the landing page.
Summary
A CTA is the invitation to the next step: start with a verb, say what they get, and keep one per piece. CTR is the click rate, clicks divided by impressions; compare it with your own usual level and read conversion rate next, because more clicks are not the same as more sales.
