A good app for custom measurements lets shoppers enter sizes the way they think of them, keeps those sizes inside what you can make, prices from them, and sends the exact numbers to your order. Appify Custom Product Options does all of that on a normal Shopify product.
Below is what to look for, one point at a time. Where a live demo product shows the point, it is linked so you can try it.
What kind of measurement input does your product need?
Products are measured in different ways. Check that the app has the field your shopper expects, not just a plain text box.
| Product | How the shopper measures | Field in Appify Custom Product Options |
|---|---|---|
| Signs, panels, frames | Types a width and a height | A number input for each, or one Dimensions option with labelled rows |
| Ribbon, trim, rope | Types one length | Length, a number paired with a unit selector |
| Flooring, wallpaper, fabric | Gives a surface area | Area, with units such as sq ft or sq m |
| Shutters, blinds | Picks whole inches, then a fraction | Two dropdowns per side |
| Floors, fences, turf | Walks the walls of a space | Room map |
The Shutters demo shows the dropdown approach. Each side has a dropdown for whole inches, from 12 to 96, and a second for the fraction, in eighths. The calculator adds the two before it works out the area.
All the field types are listed in the option types reference.
Can shoppers use their own unit?
Shoppers in different countries do not measure alike. You want one product that works for both, not a copy per unit.
Length, Area, Volume and Weight each pair a number with a unit selector, and every unit carries a conversion factor. The calculator reads the converted value.
The Customizable Curtains demo takes a simpler route. The first option asks whether the shopper's sizes are in cm or inches. The width and drop fields then follow that choice, and the price formula turns whatever was typed into metres.
A Room map has its own unit, which you pick once: feet, feet and inches, inches, centimetres or meters.
Can you keep measurements inside what you can make?
A width that is too small to cut, or too big for your material, should not reach your workshop. Look for limits on each field, a way to make a field required, and a hint on the page.
- Range and steps. A number input has a minimum, a maximum, a step and a number of decimal places. Use whole numbers only, or allow fractions.
- Required fields. Tick Required and the shopper cannot add to cart until the field is filled in.
- Help text. A line of text under the field. The curtains demo uses it to say which widths are available.
The range can change with another choice. A Limit rule sets the minimum, maximum and step on a number input when its conditions match. In the curtains demo, the width allows 50 to 2000 when the shopper picks cm and 20 to 787 when they pick inches.
The same idea works for materials. A rule can cap the width at 48 inches for a material that only comes in 48-inch sheets, and leave it open for the others. Visibility rules explains each action.
Does the form show only the fields that matter?
The app should show a field only when it applies.
A Show if rule does that. A hidden field is out of the layout, out of the price and out of the cart data. In the curtains demo, the swatches for each heading style appear only when that heading is picked.
The same rule can open a set of measurement fields only when the shopper picks Custom. Selling made-to-measure clothing walks through that form, with a size guide popup.
Does the price follow the numbers?
Entering a size is only half the job. The price should come from the size, not from a fixed amount added to a base price.
In Appify Custom Product Options, a formula can read the typed values, so area, length or volume drive the price. For rate sheets, a pricing table holds the grid. Its lookup mode decides what happens to a size between two lines: Exact, Nearest lower, Nearest upper, Nearest or Interpolate.
The curtains demo reads its price per metre from a drop-range table set to Nearest lower. A Price option can show the live amount as the shopper changes their entries.
For worked examples, see selling made-to-measure blinds by width and drop, a blinds calculator that takes sizes to the eighth of an inch and pricing custom products with multiple options and dimensions.
What if the customer is measuring a room, not a rectangle?
A width and a height cannot describe an L-shaped floor or a yard fence. The app needs a way to measure a space.
The Room map option lets the shopper list each wall with its length and turn, and watch the outline update. They can also start from a rectangle or an L and fill in the lengths. You price from total area, total perimeter, or the number of rooms.
The Flooring by the Room demo uses feet and inches and asks for a closed shape. A dropdown adds a waste percentage, and the summary lists room area, total area, perimeter and rooms. The cart line keeps the full walk and a link to one picture of all the rooms.
More on this in the flooring square footage calculator guide.
Do the measurements reach your order?
The numbers a customer typed should be on the order, in a form your team can read without emailing anyone.
- On the cart and order line. Cart properties sends each option name and value. You can add a computed number, such as area, and format it with a unit like m².
- In the app. The Orders tab lists each line with its options.
- When a customer mistypes. Edit options on the cart line reopens their entries, filled in, so they can fix a number without starting over.
The guide to editing configured products in the cart covers the setup.
Can you set it up without code?
You should not need a developer for a size form. In Appify Custom Product Options, you describe the product to Chat with AI in plain words. Say the width runs from 6 to 48 inches and the height from 6 to 36, and it adds the fields and the pricing formula.
You can attach a CSV or Excel size chart to the chat. Everything it writes is open to edit by hand.
If a price looks wrong, tell Chat with AI the price you expected. It opens the Troubleshoot tab with those choices filled in, so you can see which part of the formula to fix.
Try it before you install
- Open the curtains demo. Switch between cm and inches and read the width help text.
- Open the Shutters demo. Pick a whole number, then a fraction, and watch the price move.
- Open the Flooring by the Room demo. Add a few walls and close the shape.
- Run the same checks on any app you are weighing. Type a size outside the range, switch units, and ask where the numbers land on the order.
FAQ
Can customers enter their own measurements on a Shopify product?
Yes. Number inputs, Length, Area, Dimensions and Room map options collect typed sizes, and the price can be worked out from them.
Can I set a minimum and maximum size?
Yes. Each number field has a minimum, maximum, step and decimal places. A Limit rule can change the range based on another choice.
Can shoppers enter fractions of an inch?
Yes. Allow decimal places on a number input, or use a dropdown for the fraction, as the Shutters demo does with eighths.
Can customers choose cm or inches?
Yes. Length and Area options pair the number with a unit selector, or you can ask for the unit first, as the curtains demo does.
Do the measurements show on the order?
Yes. They are saved with the cart line and appear on the order, and the Orders tab lists them for your team.
Every size they type, priced and on the order.
Whatever you sell, however you price it · The last options app you'll shop for