This shutter calculator takes sizes to the eighth of an inch and prices them by the square foot. Getting from one to the other takes three small steps.
This is a look inside the Shutters calculator on our Shopify demo store. It's built with Appify Custom Product Options.
The shopper picks whole inches and a fraction for the length and the width. The calculator adds them up, turns the size into square feet, and multiplies it by the product's price per square foot.
What it does
The calculator opens with a color and a mount type, then four measurement dropdowns: whole inches and a fraction, for the length and for the width. A Room Name field comes next, then the build choices, from panels and hinges to louvers and the frame, each as a picture swatch.
In plain words, the price is the shutter's area in square feet times the product's price per square foot. In this demo, the size sets the price and the other choices describe the build.
Why a shutter calculator is hard to build, and how Appify Custom Product Options handles it
- A shutter size has two parts. Customers measure 35 and 5/8, not 35.6. Here the whole inches and the fraction are separate dropdowns, and a pricing variable adds them into one length.
- The rate is per square foot, the size is in inches. A basic options app prices a size as length times width times a rate, and nothing else. The shopper types 35.625 for 35 5/8, and your rate has to be per square inch to match. Here a variable divides each side by 12 before multiplying, so the area lands in the unit the rate is set in.
- The rate should live in Shopify. The total price formula reads the product's own price as the rate per square foot. Change it in Shopify and every size follows.
- A shutter order is a spec sheet. Panel layout, frame, louver size and hinges all have to reach the workshop. Picture swatches make each choice clear, and every choice lands on the order.
- Homes have more than one window. The Room Name field tags each shutter, so a customer ordering four can tell them apart in the cart and on the order.
- The choices have to survive the order. Customers can edit the size or the frame in the cart, and reordering brings the whole spec back.
One price, worked out
Here's the calculator at its opening size, 24 by 24 inches, with prices in dollars. The product's price is 64 per square foot.
- Length: 24 inches plus 0 is 24 inches, or 2 feet.
- Width: 24 inches plus 0 is 24 inches, or 2 feet.
- Area: 2 feet by 2 feet is 4 square feet.
- Price: 4 square feet at 64 is 256.00.
24 by 24 inches is 576 square inches. The formula turns it into 4 square feet first, so the rate per square foot applies as written.
The design decisions
Fractions are dropdowns that carry a number
Each fraction choice reads as 1/8, 1/4 and so on, but it holds a decimal behind the label: 1/2 holds 0.5. A variable reads that number and adds it to the whole inches.
The customer picks what's on their tape measure. Nobody has to turn 5/8 into a decimal.
Inches are a list, not a free box
Length and width each run from 12 to 96 inches in a searchable dropdown. The list itself is the size limit, so no side is shorter than 12 inches or longer than 96 7/8.
Three small variables do the math
One variable builds the total length, one the total width, and one the area in square feet. The total price formula is then just the area times the product price.
Each step is easy to check on its own. The formula editor has a Troubleshoot tab if a price ever looks off.
The product price in Shopify is the rate per square foot. There's no second price list to keep in step, and no variant for every width and height.
Pictures for every build choice
Mount type, panel layout, hinges, louvers, frame sides and frame type are all picture swatches. A customer who has never heard of a T-frame can still see one.
Most options have a tooltip too. The mount type's says what inside and outside mean.
One total, nothing else
The price summary shows only the total. With one number driving the price, there's nothing to itemize.
What arrives with the order
The calculated price goes to checkout on one cart line. Cart properties carry the color, mount, size, room name and every build choice, so the order reads like a cut sheet.
Customers can tap Edit options in the cart to fix a measurement without starting over. Later, Appify Reorder brings the order back with every choice filled in, where Shopify's own Buy again drops them.
Make it yours
- Charge for the frame. A price adjustment can add a percentage or a flat amount when a premium frame is chosen, on top of the area price.
- Price big shutters differently. A price adjustment can read the area variable and add a charge above a size you choose. A pricing table can hold a supplier's width-by-height grid instead.
- Hide what doesn't apply. Visibility rules can show frame choices only for the mount type they fit.
For more on selling window coverings by width and drop, read the guide to selling made-to-measure blinds on Shopify.
Get this calculator
Ask Chat with AI to build it in your own words. For example:
"Build a shutter calculator. Length and width each have a whole-inch dropdown from 12 to 96 and a fraction dropdown in eighths. Add the fraction to the inches, convert both to feet, and price the area in square feet times the product price. Add swatches for color, mount type, panel configuration, hinge color, louver size, frame sides and frame type, and a Room Name text field."
Chat with AI writes the options and the pricing. You check the price in the preview before you publish.
FAQ
How do you price shutters by the square foot on Shopify?
Set the product price to your rate per square foot. The calculator works out the area from the customer's measurements and multiplies it by that price.
Can customers enter fractions of an inch?
Yes. In this calculator they pick whole inches and an eighth from two dropdowns, and a variable adds them together.
Do I need a variant for every shutter size?
No. The size comes from the calculator, and the price comes from the formula. The product needs only one variant.
Can the panel layout or frame change the price?
Yes. In this demo they don't, but a price adjustment can add a charge for any choice or combination you name.
Every shutter, priced to the eighth of an inch.
Whatever you sell, however you price it · The last options app you'll shop for