Shopify AI pricing formula assistant: draft the sum, then preview

The fields are already on the product page: width, height, a gift-wrap checkbox. The price still shows the variant’s $89. Either the formula box is empty, or someone typed `width * height` while the keys are `width_cm` and `height_cm`. The storefront is not “slow”. The expression does not see those fields.

A Shopify AI pricing formula assistant is the in-builder shortcut for that gap. It does not scaffold a new calculator from a paragraph. You already built the form. You describe the pricing rule. The assistant proposes a formula and may add computed properties so the math stays readable. You run the preview. You save — or you don’t.

Shopify Help Adding variants still caps 3 options and 2048 variants. Not 100. Millimetre SKUs do not belong in that grid. Line item properties (`properties[Width]`) store the number. They do not change checkout price.

Options Price Calculator lists AI-powered generation next to the formula builder. Two flows. Create a calculator with AI drafts fields and a formula from a product description. The AI formula assistant runs inside a calculator you already have. This article is the second flow.

We already covered Math.min / Math.max in one expression. That is you typing helpers. This is the first draft of the same sum.

Variants price cells. They do not price a rectangle.

A variant is a price on a combination: Colour Red, Size L, $49. There is no `product_price + (width_cm * height_cm / 10000 * rate)`. There is no checkbox that injects `25` or `0`.

Keep real stock as native options. Do not burn an option slot on “every centimetre we might cut”. Theme math without server-side price validation is how PDP and checkout disagree.

Workarounds that still leave the formula blank

Width as variant values. 80, 90, 100. The buyer wants 92. You send a quote. The product page is decoration.

A sentence in the description. “€42 per m² plus setup.” Nobody prices from a paragraph at checkout.

Hand-typed keys that do not exist. Field keys become variables. `breedte` in the formula while the field is `width_cm` evaluates as nothing useful. This assistant does not invent extra storefront fields in this flow. It works from the calculator in front of you, plus optional custom variables for clarity.

None of that is: existing fields → suggested formula → preview → save.

What the assistant is allowed to touch

From the AI formula assistant docs:

1. Open the calculator in the Calculator builder.

2. Formula step → 4c. Formula tab.

3. Generate formula with AI.

4. Describe the logic. Apply the suggestion only after you have read it.

It may:

• replace the main pricing formula

• add or update custom variables (computed properties)

• on Premium, replace or add conditional if / then / else rules

It does not sprinkle random dropdowns onto the storefront because the prompt sounded rich.

Plans (live listing, USD)

Built for Shopify, 5.0 (27 reviews):

| Plan | Price | Formula AI | |------|--------|------------| | Free | $0, 20 uses; always free on Develop | 1 AI use, shared with “Create a calculator with AI” | | Starter | $9.99/month | Unlimited formulas; no conditionals. Branching in the prompt stays a standard formula or asks you to upgrade | | Premium | $19.99/month | Unlimited, including conditional pricing when the description needs it | | $39.99/month | draft-order checkout, admin calculator, setup | same Premium formula side; checkout is a different article |

Conditional logic, live preview, font picker, lookup tables, file uploads: Premium. Do not pin them on Free or $9.99.

Example: made-to-measure panel, not a SKU grid

Fields exist: `width_cm`, `height_cm`, checkbox `install`. Tell the assistant the unit system and whether `product_price` belongs in the sum. Docs ask for that on purpose.

A prompt that is specific enough:

> Price is product_price plus (width_cm / 100) × (height_cm / 100) × 42. Checkbox install adds 35 or 0. Round to two decimals.

Starter should return a single expression, something in the family of `product_price + (width_cm * height_cm / 10000 * 42) + install`. Premium can take “if area is above 4 m² add 20 setup” — that is branching, not a Starter feature.

A computed property such as `area_m2 = width_cm * height_cm / 10000` is fair game. Same math, easier to read. Then preview with 80 × 120, checkbox on and off. If it is wrong, do not save. Tighten the prompt. Check keys. Floor and cap helpers from the Math.min article are still manual after the draft.

Get it onto the product

1. Install Options Price Calculator. Free if you only need the shared AI turn. Starter for repeated formula drafts. Premium before you paste if/then into the prompt.

2. Name keys before you ask (`width_cm`, `material`). Labels can change later.

3. Formula → 4c → Generate formula with AI. One pricing story per calculator.

4. Review every key. Three realistic test inputs. Save only when the rule matches the business.

5. Link the calculator to the right variants. Theme app extension on the product template. Turn on server-side validation in App settings if cart and checkout must follow the app, not just the theme.

Multilingual on Starter+: translate labels. Keep the same keys in the formula.

Wrap-up

The Shopify AI pricing formula assistant is Generate formula with AI on tab 4c, on fields that already exist. One shared AI use on Free. Unlimited standard formulas on Starter. If/then on Premium. Preview is not optional.

Shopify variants stop at three options and SKU prices. The rectangle lives in the calculator. Put it on the product through the Options Price Calculator listing.