Whether you’re looking to create sophisticated calculations for your visitors, or simply work out the cost of an order – a calculator plugin can be worth its weight in gold. In this post, we’re putting some of WP’s best number crunchers to the test.

If your website needs to provide calculations, you can bet there’s a free WordPress plugin out there to help you do it.

Many calculation plugins can also be used in combination with third-party apps, giving you access to thousands of extra features and options.

All adding up to… (adding machine noises)… an amazing website!

Today I’m showing you several free calculator plugins and how they can all help in different circumstances.

By the end of this article, you should hopefully have enough data to crunch the numbers for yourself and work out what’s best for you.

Just please be gentle when punching the numbers in (unlike Dev Man below).

Dev Man with a calculator, about to punch it, because of WordPress Calculator Plugin.
This calculator’s numbers might be up.

We’ll look at:

  • Do you need a calculator plugin?
  • Several specific options (and their uses)
  • Using Forminator for calculations

Speaking of Forminator, it’s our own form plugin (with calculations) here at WPMU DEV and later on in the article we’ll take you through a complete tutorial, showing you how to set up basic calculations for your site-forms.

Would it make a nice addition (or subtraction) to my website?

It depends on what users want to calculate on your website. You can solve this problem by factoring in your market needs.

Chances are you’ll need one, or could benefit from one if you have a website for any of these categories:

  • Mortgages
  • Financial loans
  • Debt Reduction
  • Student Loans
  • Weight-loss
  • Math
  • Travel
  • Statistics

Even websites for a Zodiac, love calculator, or – if you’re a doomsday prepper — countdown clock until the end of the world (yikes!), could all benefit from having a calculation plugin.

Adding Up Your Options

WordPress has some very specific plugins for various calculations.

For example, if you have a mortgage company, and your visitors need to calculate a mortgage payment, a good option is the Responsive Mortgage Calculator.

Responsive Mortgage Calculator.
Need to allow visitors to calculate their mortgage payments? This calculator plugin is a great choice.

It’s a free jQuery widget and shortcode that’s made to easily fit into any theme, on any device, at any size. It’s made for any real estate agent that is constantly on the move showing properties.

The plugin relies on www.mlcalc.com service to show the calculation results and you must agree to its terms of use.

Some of the features that are included in this are:

  • Price of the home
  • Interest rate (fixed rate)
  • Selectable payment period
  • Amortization period
Example of responsive mortgage calculator wordpress plugin.
An example of the mortgage calculator.

You can also select the interest rate compounding period for your region, set a fixed payment period, and add your CSS classes.

Get the Responsive Mortgage Calculator here.

Doing some (number) crunches?

Are you a personal trainer? Have a weight-loss service? Well, a BMI calculator might be a perfect inclusion on your website to do the heavy lifting.

A simple, free option is the BMI Calculator Plugin.

BMI calculator homepage.
The BMI Calculator plugin helps with all of your heavy (number) crunching.

It was created so you can include a body mass index calculator to your blog by using [bmi] shortcode.

It has three built-in styles:

  1. Material Design
  2. Bootstrap
  3. Default (your own theme’s style)
BMI calculator example.
Example of the BMI calculator.

Overall, it’s simple to implement/ install, and enables BMI calculations as advertised.

Get the BMI Calculator Plugin here.

And then there’s also the CC BMI Calculator.

CC BMI Calculator homepage.
CC BMI Calculator homepage.

This free plugin can calculate in imperial or metric units.

The calculator itself is also highly customizable. There are options to change the color of the background, borders, and text. This is nice so that you can adjust accordingly to match your website’s theme.

Example of the CC BMI Calculator wordpress plugin.
Example of the CC BMI Calculator.

It can be placed on the sidebar as a widget or incorporated into any post or page with its shortcode.

Get the CC BMI Calculator Plugin here.

Because I’m Free. Free Formin’

Another great option for a free calculator plugin is our very own four-eyed friend, Forminator.

Forminator image.
“Hi.”

We have to talk about him, because a lot of calculations, forms, checkout processes, and more can be all achieved with his help, all in one place. And he’s an all-around nice guy, too.

What exactly is Forminator (and what does it have to do with a WordPress calculator)?

It’s a completely expandable form builder plugin. You can create service estimators, registration forms, and it comes with payment options for customers, such as PayPal and Stripe.

Forminator also makes it easy by including drag and drop blocks. You can rearrange and adjust however you’d like by simply moving the blocks around in Forminator’s dashboard.

What’s really great is integration. You can integrate your calculator, and form, with 1000-plus apps, such as Zapier, Trello, MailChimp, Hubspot, Google Sheets, Slack, and more.

He can get the calculations done.

There are thousands of combinations for adding value to your site with Forminator. For example, you can:

  • Sell a tee shirt with size, color, prices, and tax variations
  • Add a BMI and/or calorie intake calculator
  • Create a loan calculator and embed it on your site
  • Include a quote or service
  • Add registration forms

Computing Whether To Use Or Not?

To help you decide Forminator is the way to go for your calculator plugin. Here’s a small step-by-step example of what he can do…

Let’s say you want to sell a new comic book. It’s an action-packed comic that features all of our superheroes here on WPMU DEV.

First off, as avid superhero fans, we love that idea! Second of all, you need to have a calculation of the different books.

There’s the regular one that is priced at $3.99, the deluxe edition, priced at $5.99, and then the autographed version (signed by Dev Man himself), priced at $10.99.

The first step is to install Forminator for free.

Landing page for Forminator.
The Forminator dashboard.

Once you have it installed and activated, go to the Forminator dashboard. You’ll notice that you have three options:

  1. Forms
  2. Polls
  3. Quizzes
Forminator dashboard.
The Forminator dashboard.

Since you need a calculating form for sales, you’d want to go with a regular form. Go to Forms and hit ‘Create’.

This will then take you to a template option. You’ll create one from scratch, so hit the ‘Blank’ option. From there, hit ‘Continue’.

Choose a template.
Some temp(late)ting choices.

Next, you’ll be prompted to name the form.

Enter a name in Forminator.
A fitting name for this.

After hitting ‘Create’, you’ll be in the Edit Form dashboard.

Edit form in Forminator.
The Edit Form dashboard.

This is where you can add all the information needed and create a form for anyone that would love to order a comic book.

Say you’re going to charge them on the spot and ship it to them. If that’s the case, you’ll need:

  • Name
  • Address
  • Email
  • Phone number
  • Comic book options
  • Payment

A great thing about Forminator is you can choose to have the customer purchase right there on the spot with PayPal or Stripe at no cost. (When we mentioned this was a free plugin, that means for everything.)

Click the ‘Insert Fields’ to get all of the information in one place.

Insert fields area in Forminator.
Click the purple button.

You’ll see that most of the field types are already ready to go!

Pick and choose the options by clicking on them. Once you do, they’ll turn blue and have a little checkmark on the upper-right hand side of them. You can click several at once.

Insert fields options in Forminator.
All of the boxes in blue are the selected ones.

Now, click ‘Insert Fields’ and then you’ll see that it’s all compiled for you under the WPMU DEV Comic Book.

You can rearrange these blocks however you’d like. It’s a simple drag-and-drop method. For this example, we’ll have it as:

  • Name
  • Address
  • Phone
  • Email Address
  • Select
  • Credit/Debit Card
Showing all fields in Forminator.
You can see all of your preferences on this screen. You can drag-and-drop here and arrange any way you want.

What you’ll do now is edit the ‘Select’ box. You can see that, if you wanted to, you could duplicate or delete it here, too.

Edit field in Forminator.
The drop-down occurs when clicking on the block.

Click ‘Edit Field’.

Once here, you’ll choose what type you’ll want for this form, Single or Multiple. Go with Single. We’ll also add a label, description, and then below that, you’ll see Options.

Option area in Forminator.
The Options area.

There are only two options by default. We need three (remember, we have that amazing signed edition that will be available).

Just click the ‘Add Option’ button below and it will add a 3rd option.

You’ll notice a Calculations tab. Here is where, if you’d like, you can add calculations to each option.

Calculations value page for Forminator.
You can specify the exact calculations needed here.

The calculations must be a numeric value only.

Calculations field in Forminator.
An example of adding numeric values to the calculations.

To get the calculations to function, add Calculations to your form.

Calculations tab in Forminator.
The Calculations option.

Then, you can go into it and add formulas for specific needs. In this example, we’ll add one for a sum. You can also use – / * etc.

Sum formula example.
Example of a sum formula.

The calculations will then work with your Fields.

Calculations can be adjusted accordingly to your use. You can add sales tax, discounts, and more.

You can also adjust the Settings, Styling, and Visibility.

Once you have everything set up the way you want, you’ll need to connect a payment option with Forminator, since something is being sold. Let’s go with Stripe. If you don’t have a Stripe account, it’s easy to set up and you can here.

You do this in the Settings area.

Settings area for Stripe and PayPal in Forminator.
Settings option for Stripe and PayPal.
Not connected to Stripe settings screen.
It will tell you if you’re connected to Stripe or not.

You’ll simply log in to Stripe, and copy and paste your Publishable Key and Secret Key into Forminator.

Stripe Publisher Key.
The Stripe Publisher key inside Stripe. You’ll copy and paste this into Forminator.

Stripe has a Test and a Live mode. When you are setting this up, it’s best to stay in Test. In Test mode, no purchases can be made. When it’s published on your website, you’ll switch it to Live and will be able to start taking customers’ orders.

Now, you’re all set to go! You can always hit ‘Save Draft’ if you don’t want to have it published yet. Also, be sure to preview it.

Preview of the Forminator form.
Preview of the form.

In the preview, you can see that the dropdown has options for the comic book in it.

Forminator dropdown with comic books.
The different comic book options.

If you’re happy with everything, hit ‘Publish’ and you’ll be good to go!

Just don’t forget to go back to your Stripe settings and change it from Test to Live.

Forminator keeps track of all of your forms in one spot, so it’s easy to get back to at any time. Not only that, you can keep track of your stats for it, edit, and more.

When you’d like to add the form to a page or post, simply copy the shortcode for it.

Copy the shortcode from Forminator.

Here’s a look at what it will look like if pasted in the middle of a random post on WordPress.

Forminator shortcode pasted.
What the Forminator code that you’ll paste into WordPress pages or posts will look like.

And here’s the form in action.

Live preview of Forminator.
What the form looks like live.

You can do a TON of customization on it, so get as creative as you’d like.

For example, you can:

  • Change fonts
  • Add sales tax
  • Change colors
  • Add images
  • Resize
  • Create bold boxes

And lots more…

Forminator, again, is a great go-to option for creating calculations. Any calculation can probably be created with this plugin and tweaked however you wish. This comic book example is one of many, many options.

If you’d like to watch a demo of setting up an ordering form, be sure to check out the video below.

We all at WPMU DEV love it not just because we’re biased. The fact that it’s so customizable, easy to use, and FREE, you can’t go wrong. Plus, if you want to use the Pro version, it comes with 24/7 support if you do have any questions or need help.

It’s All a Numbers Game

When it comes down to it, a calculator plugin is either…

Mandatory for your site (for example, you need to know the amount of something with tax).

Or a useful feature that adds value to a website, but not mandatory (e.g. a loan calculator to give potential customers estimates before reaching out).

There are many options when it comes to adding a calculator plugin. With a little bit of searching, you can find one that’s perfect for your website.

As you can see, calculator plugins can be beneficial as a lead magnet, sales page, estimator, and more. As long as the numbers work in your favor.

Keep in mind, if you’d like to give our recommended Forminator a try, we have a free 30-day trial that comes with support, and additional plugins for your site.

With all that being said, I hope this added-up into providing you with a calculated decision on your next plugin for WordPress.