If you price by a rate card, the fastest way to formula pricing on Shopify is to describe the card and let the app build it.
In Appify Custom Product Options, you tell Chat with AI how you price, and it sets up the options, the rates and the formula. Everything it builds stays yours to read and edit.
Here's one product set up from start to finish, with three prices you can check by hand. It's a cut-to-size panel, priced by area and material.
The rate card we're setting up
These are made-up numbers, in dollars. The shopper types a width and height in inches and picks a material.
| Material | Rate per square foot |
|---|---|
| Wood | 2.50 |
| Acrylic | 4.00 |
| Metal | 6.50 |
Two more rules sit on top: a minimum price of 10 per panel, and a flat setup fee of 15.
Step 1: Describe it to Chat with AI
Create a calculator, then open Chat with AI, the panel beside the editor. Describe the product the way you'd explain it to a new hire:
Try this prompt: I sell cut-to-size panels. Customers enter width and height in inches and pick wood, acrylic or metal. Price is the area in square feet times a rate per square foot: wood 2.50, acrylic 4.00, metal 6.50.
The preview updates as it works. Already have the rates in a spreadsheet? Drag the CSV or Excel file onto the chat and ask for them as a table.
Step 2: Know what it built
You don't have to write any of this, but it helps to know the pieces:
- The size, worked out once. The area is a pricing variable, so every formula and rule reads the same number.
- Your rates, in one grid. The rates sit in a pricing table that's available to every calculator in your store. Change a rate once and each calculator picks it up the next time it loads.
- One formula for the price. The total price formula multiplies the area by the rate for the chosen material.
Step 3: Add the minimum and the setup fee
Set the Minimum price to 10, next to the total price formula. The formula runs first and the minimum applies to its result.
Then add the setup charge as a fixed fee of 15. It comes after the minimum, shows as its own line in the price summary, and is never reduced by discounts.
Step 4: Check three prices by hand
Switch the preview to Draft, enter a few sizes, and compare the price with your own math. Here are three to try, for one panel each:
| Panel | Area | Area times rate | After the minimum | With the 15 fee |
|---|---|---|---|---|
| 24 x 36 in, Metal | 6.00 sq ft | 39.00 | 39.00 | 54.00 |
| 24 x 36 in, Acrylic | 6.00 sq ft | 24.00 | 24.00 | 39.00 |
| 8 x 10 in, Wood | 0.556 sq ft | 1.39 | 10.00 | 25.00 |
The small wood panel is the one to watch. Its area price is 1.39, the minimum lifts it to 10.00, and the fee lands on top.
Step 5: Publish it
Choose the products the calculator applies to, then click Publish v1 in the editor header. Saving alone doesn't publish, so your changes stay a draft until you do.
Each order carries the shopper's width, height and material for fulfillment.
Prefer to build it by hand?
Everything chat builds is a normal setting you can type yourself. The two formulas behind this panel are short:
-
The area variable:
INPUT("WIDTH") * INPUT("HEIGHT") / 144, so inches in, square feet out. -
The total price formula:
VAR("AREA") * TABLE("materials", OPT_TOKEN("MATERIAL")), the area times the rate for the chosen material.
Change or read a formula without knowing the syntax
Every formula field in the formula editor has tabs above it:
- Describe with AI: type what you want, like "charge 2.50 per square foot with a 25 minimum", click Generate, and review the formula it writes.
- Explain formula: turns an existing formula into a step-by-step plain-English explanation. Handy for a formula someone else wrote, or one you wrote months ago.
- Troubleshoot: runs the formula for the choices in the preview and shows what every part is worth.
What to do when the price looks wrong
Click Price looks wrong? under the preview price. It opens Troubleshoot for the exact choices on screen. Type the number you expected into I expected, and the tab searches your tables for it.
On a setup like this one, it catches the usual slips:
- A choice that matches no row: the choice reads Metal, but the table row says Steel. It offers a one-click fix.
- OPT where OPT_TOKEN belongs: the table gets a price when it needed the choice's token.
You can also tell Chat with AI, "24 by 36 in metal should be 54". It opens Troubleshoot with those choices filled in and the expected price entered.
Build one product end to end, check three prices by hand, then copy the same pattern to the rest of the catalog.
Where to go next
- What formula pricing covers: what formula pricing actually means in Shopify options apps.
- Formula or table: formulas vs pricing tables shows when each one fits.
- Bigger orders, smaller prices: tiered and volume pricing for custom products.
- Prices that depend on other choices: conditional pricing rules.
FAQ
Do I need to write formulas myself?
No. Chat with AI builds the setup from a description, Describe with AI writes a single formula from a sentence, and Explain formula reads one back in plain English.
What's the simplest formula for pricing by size?
Area times a rate. Work out the area once as a pricing variable, then multiply it by a rate from a pricing table.
Can one rate table price several products?
Yes. A table made on the Pricing Tables page is available to every calculator, so a rate you change once updates each product that uses it.
Where does a setup fee go?
In fixed fees. A fee is added after the formula and the minimum, shows as its own line, and isn't reduced by discounts.
Describe your rate card. Sell from it today.
Whatever you sell, however you price it · The last options app you'll shop for