An online calculator gives the result in the browser: the visitor enters the numbers and sees the total on the same page. A site calculator does this for a service price, before anyone contacts you. In FormDesigner you build the same calculator without code: add the fields, set the formula and paste the ready code into any page or CMS.
Try the example below, then build your own.
What is an online calculator
An online calculator is a page that counts while you fill it in. Nothing to install: the result appears in the browser.
A site calculator is that tool on a business website. The visitor picks the options, sees the price of a service or an order, and only then sends a request. You do not need a development studio to put it on a page. The calculator is assembled in a visual builder and embedded as ready-made code. Formulas and prices are set once; the visitor only sees the result.
What a site calculator consists of
A simple site calculator is a short set of fields. Each one changes the total:
| Element | What the visitor does | Example |
|---|---|---|
| Drop-down list | Picks one option | Type of work: cosmetic repair or a full renovation |
| Slider | Sets a number | Area, 40 m² |
| Checkbox | Adds an extra service | Waste removal |
| Switch | Turns an option on or off | Urgent delivery |
| Currency rate | Sees the total in another currency | Price in EUR, total in USD |
| Send the result | Leaves a request or pays | Email, CRM, or payment |
A repair calculator shows the pattern. The visitor enters the area and picks the type of work. The formula is area × rate per m² + extra services. At 40 m², a rate of 25 and extras of 150, the total is 1,150. That number is on the page before the visitor sends a request.
Where an online calculator works best
A calculator keeps visitors on the page longer and turns the question “how much will it cost?” into a request with the numbers already filled in. It works best where the price depends on several options: construction and repair, transportation, mortgages and loans, cleaning, furniture, windows, cosmetics and beauty services. More on the business side is in the article about the benefits of a website calculator for marketing.
A calculator gives a potential client a clear price without a long exchange of emails, and gives you a request from someone who already knows the approximate cost. With an online calculator builder like FormDesigner, you can add one to any page without code. Reply to these requests quickly: the faster you respond, the more of them turn into orders.
Ways to add a calculator to a website
There are four common ways to put a calculator on a website. You can write it yourself in HTML and JavaScript, which gives full control but needs a developer and someone to maintain the code whenever prices change. On WordPress you can use a plugin with calculated fields: it is convenient if the whole site is on WordPress, but it works only there and needs regular updates. Ready-made widgets are quick to embed, though simple ones often cover a single formula and carry the vendor’s branding.
The fourth way is a form builder with calculation fields, like FormDesigner. You assemble the fields and the formula visually, add logic, a request form or payment after the total, and paste the code into any site. This is the approach the rest of this article follows.
Creating a calculator in FormDesigner: three steps
Creating a calculator does not require programming. It takes three steps:
- Add the fields and the formula. Drop-downs, sliders, checkboxes and a “Formula” field are assembled in the builder; the visitor sees the total before submitting.
- Set the logic. Show only the fields and pages that fit the visitor’s choices.
- Publish. Copy the ready code and paste it into your page. It works on any site and CMS, and later changes are made online in your account.
With the FormDesigner calculator builder for any site you can quickly create calculators with different sets of parameters. Choose a template or start from a blank form, enter your prices and options, and check the result in the builder: every change is visible right away. Themes and your own CSS let you match the calculator to the design of your site. The total from the calculation field can go straight to the payment terminal, so the customer can pay right after the calculation. To see it in action, look at a calculator that prices a job.
When a price changes, edit the formula in your account. The page on the site updates without a developer and without a new embed code. Branches, currency rates and payment after the total are set in the same builder. FormDesigner is an online form designer that also builds quizzes, surveys and booking forms.
How to put the calculator on your site
Once you have copied the code, paste it into a block that accepts HTML. On WordPress that is the Custom HTML block. In Wix, add an Embed Code element and choose the code option. In Squarespace use a Code block; some custom-code features depend on your plan. In Shopify open the theme editor and add a Custom Liquid block where the calculator should appear. The names of blocks can differ between themes and versions, but the idea is always the same: an HTML or embed block, then save and check the live page.
If you prefer not to touch the page at all, the calculator can be opened from a direct link or shown as a pop-up window.
Calculator examples by industry
Different businesses use the same pattern with different formulas. A repair or construction company multiplies the area by a rate and adds extras. A transport company calculates by distance and weight. A lender shows the monthly payment from the amount and the term. A car rental service counts days and options, as in the Rent a car template. An insurance agency can use a calculator like the MTPL calculation, and a detailing studio can price the work by car class and services, as in the detailing template. For more ideas, browse the templates. Formulas and examples for repair, cleaning and mortgage calculators are in the article on cost calculators for a website.
Tips for a calculator that converts
Put the calculator where the visitor asks about the price: on the service page, next to the price list or at the top of the page. Keep the calculator simple: a few clear fields and a visible total, and every parameter should change the result. Too many parameters make visitors leave the page.
Set sensible default values so the visitor sees a result right away and can adjust it. After the total, give one clear next step: a request, a callback or a payment. Check the calculator on a phone, because fields and buttons must be big enough to tap. If you use web analytics, look at where visitors leave: a field that people abandon is the one to rewrite. To increase the average order, add a discount for larger volumes or a bonus for a repeat order.
Calculator not showing?
If the calculator does not appear after you paste the code, the first suspect is the block: text blocks often strip scripts, so use an HTML or embed block instead. If it looks cramped on a phone, give the container the full width of the column. If the total is wrong, check that each field is connected to the right place in the formula, and test with simple numbers whose result you know.
