Looking to create a WordPress custom calculator? With a WordPress calculator plugin, make a shiny custom calculator in WordPress today! Here’s how.

Approximate read time: 6.5 minutes
When you think about calculators, what comes to mind?
Nightmares of tax season? Flashbacks to a high school math exam? If you connect calculators with awful math-based tasks, you aren't alone.
But we've got some good news: calculators don't have to be scary.
And in this post, we'll show you why.
So, let’s show you how to create a custom calculator for your website in a few easy steps.
Why create a custom calculator for your website?
Can a calculator really have a big effect on your website?
Actually, yes.
A report found that when people use interactive content, like calculators, they learn more, see the differences between you and competitors, and are more likely to share it with others.
Basically, interactive content helps people understand better, and they like it more. Plus, calculators can be great lead generation tools. For example, imagine you’re a travel agency, and you want to help travelers calculate their trip budget.
With a few simple fields, you can have a custom calculator ready to help.
And that’s not the only area a calculator can help! You could also use them like this:
- Financial calculations
- E-commerce and shipping
- Health and fitness (like a BMI calculator)
- Real estate
So, now that you know how you can use a calculator, let’s get to making one.
How to create a WordPress custom calculator
If you want an easy way to create calculators in WordPress, you can’t go wrong with Formidable Forms.
It’s the most advanced forms plugin for WordPress, making it simple for anyone to create a calculator — no matter the skill level.
To begin, you’ll need a license key with Formidable to build your custom calculators. So head to our pricing page and grab the plugin at one of our excellent prices.
So, let’s get started!
Step 1: Install and activate Formidable Forms
First, go to Plugins → Add New in your admin panel in WordPress.
Next, search for Formidable Forms and click the Install button, then click Activate.
After that, go to Formidable → Global Settings and click Connect an Account.

This will bring you to a login screen where you can login and then click Connect and Install Formidable Forms Pro.
Now you should see your license displayed in your settings.

Now it’s time to create a form!
Step 2: Create a form and add fields
To start your form, go to your WordPress dashboard, and Formidable → Add New.

Next, you have the choice to use one of our pre-built form templates or choose Blank Form to start from scratch.
For our example, we’ll be building a travel budget calculator. So we’ll click Blank Form to create our own.

After, give your form a name and then click Create.
Now, it’s time to add fields. And it’s easy with Formidable’s drag-and-drop form builder.
To start building, choose the input field, and drag it to the form.
That’s it.
So, for a percentage calculator, add three fields: the number, the percentage, and the value.
That’s it.
So, in our example, we’ll add a couple fields here:
- Text field
- Number field
- 2 Date fields
- 4 slider fields
We’ll rename each of these fields:
- Text → Destination
- Number → Number of travelers
- Date fields → Travel Start Date/Travel End Date
- 4 slider fields → Accommodation/Food/Activities/Extras budget
So, our form will look like this:

You can adjust the field label in the left-hand tab under the Field Options.

So, now we need to get some total fields. It would help if travelers could get a total, as well as how much it costs per traveler and per day.
That way visitors have a more thorough cost breakdown.
Step 3: Create a Total field
This step is the only one that requires a little bit of math.
But don’t worry, you won’t be reliving your school days here! So, to get started, add a number field to your form.
To make sure users can’t edit the field, click the Read Only checkbox.
You can label it whatever you want. We’ll stick with “Total Budget.”
Next, in the Field Options, click Advanced, then click the calculator icon, and find Default Value. This is where you’ll type in your equation.
So, for our example, we just want to add the Accommodation budget, Food budget, Activities budget, and Extras budget.

So, we would add the shortcodes next to each field name: [382]+[383]+[385]+[384].
Now, as we adjust each budget, the total field will show the total! Pretty easy, right?
But, we want to make the form a little more in-depth.
So, we’ll add three more number fields for more totals: Length of trip, Per day, and Per traveler.
The formulas for each of these are pretty simple:
- Length of trip: [379]-[378]+1 (End of trip - Start of trip + 1)
- Per day: [376]/[386] (Total budget/Length of trip)
- Per traveler: [376]/[367] (Total budget/Number of travelers)
Plus, we added Page Breaks to break up the pages and make the form more readable.

So, it’ll look something like this:

Remember this is just one example of what you can do, and we’re barely scratching the surface.
So, let’s add some more functionality to our calculator.
Step 4: Add conditional logic
Formidable has many fields for you to play around with and make your calculator unique.
And there were a few ways we though we could improve it.
For example, Formidable Forms has conditional logic. If you’re unsure what that is, it’s your ability to hide or show fields based on what a user chooses.

So, in our calculator, we added a Radio field so users can select how they’re traveling: flying, driving, or train.
Then, we added a few more Sliders so users can input more information to add to their travel budget.
Then, we added conditional logic to each of these so they only show when a user chooses that travel option.

This makes the experience much more interactive for your user and increases the chances they use your calculator.
Step 5: Style your calculator
A basic calculator works and will get people to use it.
But adding an eye-catching calculator to your website? That’ll increase conversions in a big way.
And that’s where Formidable’s Visual Form Styler comes in.

With a simple click, you can change the entire style of your calculator using one of Formidable’s pre-built templates.

Or, customize it yourself and handle every detail! The choice is up to you.

For ours, we’re using the Sleek & Smooth template to make things quick.
Step 6: Add additional fields
Formidable has tons of fields for you to expand the abilities of your calculator.
You can add repeater fields, credit cards, and even use AI when you build an online calculator!
For example, we can add an AI field to our last page when it shows us the totals. Using this AI field, we can have it use the information the customer entered by “watching” the fields and then create an itinerary for the visitor!
But, we don’t want it to run if someone doesn’t want the itinerary. That’d just be a waste of time and credits!
So, we added a checkbox with the label, “Want an itinerary?” If a visitor checks it, then it’ll start creating their itinerary.

What’s even cooler is that you have control over how your AI acts! All you have to do is set the Guide Prompt so it knows how to use the data and what to do.

It’s best to keep these prompts short but detailed. But once you figure out how to use your AI, it’s powers are pretty incredible.
Step 7: Gather leads with your calculator
Creating a custom calculator for WordPress is a great way to get people to your website.
But it doesn’t give you a way to connect with those website visitors and turn them into subscribers or customers!
But calculators are actually perfect lead generation tools!
And using it to your advantage is crucial. You could add an email field and offer to have the calculator results sent to them, or add a phone number field and use it as a way to reach out to the customer about a quote.
Since we’re generating itineraries for visitors, we think some would love to have it emailed to them. So we’ve added an Email field to our form and set it up an Email Notification action so it sends an email to them with their itinerary.

Plus, we changed the submit button text to “Send my itinerary” so they know exactly what to do next. Having a clear call-to-action is a huge part of increasing conversions.
But we can also use this opportunity to see if they would like to join our newsletter or one of our upcoming tours!
So, under Settings, we can go to Actions & Notifications.
Under the tab Send Email, we can begin to customize our email.
So, we’ll change the To field to the field key for the Email on our form. And we’ll write a little message, then attach the field key for the AI field.
This will show the AI’s response in the email. Remember that your field ID may be different, so be sure to check yours.

Step 8: Add a calculator in WordPress
Okay, so you’ve created your calculator, but how do you add a calculator to a website?
Simple.
First, go to the post or page on which you want to show the calculator and add a new WordPress block.
Next, search for Formidable, and add the Formidable WordPress block.
Last, choose your calculator from the dropdown menu, and you’re finished!
Update your page/post, and you’re good to go.
Step 9: View your customer journey
Now that your calculator is live and people are filling it out, it’d be nice to know how they’re getting to your page, right?
Are they going to specific pages? Clicking a certain button and ignoring others? What exactly are they doing?
For that, you can use the Formidable User Flow feature.
By enabling one add-on, you get a detailed report for every person that completes your calculator form.

Using this information, you can adjust your customer journey so that you maximize the visibility of your calculator.
And more visibility means a higher chance for conversions.
So these are just a few ways Formidable can help you. If you want even more, then check below 👇
Give your calculators superpowers with Formidable Forms
Now that you’ve learned how to make a custom calculator in WordPress, you’re only scratching the surface.
No matter what type of simple calculator you need, all the power to make it is now in your hands.
Need to make a price calculator? How about a loan calculator?
It doesn't matter the type of online calculator for WordPress you need. Formidable is the WordPress calculator plugin for the job.
Here are a few examples.
Grow your business with Formidable Forms
Let’s imagine you run a real estate business.
A website calculator is one of the most helpful things you can offer customers. You can give them a way to calculate their monthly payment and interest rate to know if they can afford a house.
And this applies to almost all industries!
Here are a few more examples of how you can use a calculator:
- Physical trainers offering weight-loss or BMI calculators
- Real estate agents helping people with a mortgage calculator
- Businesses using PayPal order forms
- Companies using ROI calculators to get better results
- Business creating pricing based on large amounts with a measurement price calculator
- Quote calculator for estimates
A calculator is suitable for your website because it’s excellent for visitors. Helping them means helping yourself.
You can also collect users’ email addresses for email marketing and lead generation. All you need to do is require an email to get the results of your calculator, and you are set!
So, let’s show you how to make a calculator in WordPress with a plugin.
Read More: 6 Ways to Use Calculators on WordPress Sites
Use Formidable as a cost calculator builder
Do you have an eCommerce site and want an easy way to show prices to customers?
Then Formidable Forms is the perfect price calculator plugin for WordPress for you.
A cost calculator builder is the only employee you need. And a good one simplifies things for you enough that you barely have to do anything.
Well, that’s exactly what you get with Formidable and its web calculators:
- Automatic cost estimation
- WooCommerce integration
- Pre-made calculator form templates
- Visual Form Styler to create a stylish cost calculator
So, whether you’re selling 100,000 products a month or 10, Formidable is here to help you.
Help people manage finances with a WordPress custom calculator plugin
Imagine you own a car dealership and help customers find the best financing for their cars.
Formidable’s car loan calculator template helps you get a calculator on your WordPress website fast.
And that saved time means you start helping customers today.
You get a new business lead with each customer that fills out your car loan calculator.
And this applies to any investment calculator type you need!
Power up people’s fitness with a fitness WordPress custom calculator
Body Mass Index (BMI) is a term that gets thrown more than a football on Sunday.
But that’s because people are looking to find out theirs.
And what better way to attract people to your fitness website than with a BMI calculator that’s easy to use?
Well, Formidable helps you do that, too.
Formidable helps you create an online calculator that meets your needs. All of ‘em.
All your calculators. One simple WordPress plugin and custom calculator builder.
Get Your Ultimate Calculator Plugin!
Are you ready to create your WordPress custom calculator?
As you can see, using WordPress to create a calculator from scratch can be complicated. It’s possible, but it may involve figuring out formulas and doing some math.
But no checking lines of code, changing input types, and other difficult tasks.
If you’re wondering, “How do I add a mortgage to my WordPress calculator?” Don’t worry. We’ve got you covered.
You can easily add a mortgage calculator to WordPress with Formidable.
And, Formidable doesn’t only handle calculators. Contact forms, quizzes, and anything else you can imagine are all possible with Formidable.
Now is your chance to make it happen. Get ready to make an online calculator!
So, wondering, “How do I create an interactive calculator for my website?” Well, we answered that question, too. And you can find all your interactive content needs in this guide. It’s time to get your page builder and create a calculator website!
Also, follow us on Twitter, Facebook, and YouTube for more great tips on how to make a calculator website!
Read more WordPress calculator blog posts
Did you know that Formidable Forms is one of the fastest WordPress form builder plugins available today? If you're not already using it, get started with our free plugin or the full-featured pro version!
I definitely agree about not adding a bajillion plugins to your site. Conflicts aside, abandoned plugins and security concerns abound. Thanks for adding this to Formidable!
Formidable is our "swiss army knife" of plugins for WP. We install it on almost every site we develop. I'm not sure adding another small calc plugin is a big problem, but since we already have FF installed, it's easy enough to create things like calculators.
Thanks for the kind words! Glad you love Formidable Forms.
Do you have a solar energy calculator plugin?
Hi there, Thanks for your question. We don't currently have one, but our calculations are pretty powerful, so you could either create your own, or if you have an example to show us with the calculations involved, we could probably build a template to add to our library.
Whenever recommending Formidable Pro to other WordPress users on forums or Reddit I always say that the biggest advantage is that the team adds new functionality regularly and seems to listen to the community. And here we have additional functionality I can add. Thank you
Thanks so much for recommending Formidable Forms! We really appreciate that. We are always working on new features to add more value to our platform. We hope you love what is coming next!
My favourite calculator I created with Formidable Pro was a floor area calculator for a carpet company.
I love the computer functionality Formidable Pro.
Very useful article on how to build a calculator with wordpress. I've found the team quite responsive and helpful.
Thanks for the kind words…I’ll pass your praise on to our support team.
My company switched to Formidable Forms abot 2 years ago after being frustrated with the horrible interface of Gravity Forms. Formidable is beautiful enough that our designers love it, and feature full enough to keep our developers happy!
Thanks so much for sharing! We always love hearing about the things people love about Formidable Forms.
This is great. Thanks for the tutorial. Excited to try it out on a project!
Awesome! Calculators can add a lot of user engagement and make your site better! Best of luck on your project!
I think it could be a good idea to implement a calculator in the same page I have a real state offers, so the client could be calculate costs easily
Yep, we have many pre-built real estate and mortgage calculators as well to make your life a bit easier.
Nice!, love how versatile FF is!
I love the possibility to addvalue to my content with easy-to-use calculators! Thanks a lot!
You're welcome! Glad you are enjoying the calculator functionality built into Formidable Forms.
The sheer versatility of this plug-in continues to blow my mind. I'm amazed every time I find a new way to use it, pretty sure I'll end up using this on a new project I'm working on.
Formidable is one of the most powerful WordPress plugins, yet it is easy to use. The premium templates offer great functionality. These guys know what they are doing and they do it right. The documentation and support are superb.
Its great to see what the possibilitys are with Formidable and Im very curious about future features thats why I use an Elite subscription.
Great work guy's!
Thanks for the kind words...We have some big plans in the works. Should be a fun and exciting year.
An amazing plug-in to have. I usually install this plug into my clients website. Since most of them are not technology savvy, I believe it helps them a ton due to the lack of technology experience that they might have otherwise. Great job formidable team
Awesome! We always strive to make our customers look like rock stars for their clients. Part of this is making sure the transition when handing off a site to the client goes smoothly. Thanks for your Comment!
Hi team!
Well done on the amazing job! I love Formidable plugin so far.
Quick question: could you possibly help me create a template for the calculator I want to build?
It's a bit more complex than I can handle with the current options available. Do you mind if I run it by the team and you could point me in the right direction or help me create a bespoke template?
It's essentially an annuity type pension calculator which should be a CTA to lead into an option for my customers to make an investment or set up regular savings.
Can we make a Vaccine calculator. Its simple adding formula that add on no of days in Date of birth entered by a person. Outcome is displayed as vaccine required every age milestone...If yes plz let me know.
Hi Rajiv,
Our plugin can do limited date calculations out of the box. These typically include calculating the number of days between two dates, or calculating an age.
Our plugin can't currently add days to a date so I don't think it would be a good fit for your application. This functionality is on our feature request list, but it isn't on our current roadmap, so I don't have an estimate on when it would be available.
This blog is really helpful
Hello,
I want to create various calculators for my site, such as BMI, how much protein per day, how many calories per day, measure body fat at home, calculate calories burned RMR, etc.
My question is will I be able to do it with this plugin?
They should also be in Bulgarian, and I should point out that I have no coding skills!
Thanks in advance,
Rado
We have BMI calculators already built out and available as templates. You should be able to create calculators for these other items as well. No coding skills required.