Calculate extra prices

Development alpha 0.1.0-alpha.1 · Updated 20 September 2026

Set extra prices

A fixed field price applies when that option has a nonempty valid selection. Choice-level extras are added separately.

Pro adds these calculation methods:

Percentage: percentage of the product catalog unit price. It is not a percentage of the entire cart.
Once per cart line: one extra amount for that customized line. Increasing its quantity does not multiply that particular charge. Different personalizations form separate lines and each receives its own charge.
Per character: counts the selected value’s characters, including internal spaces. Leading and trailing spaces are removed.
Formula: numbers, parentheses and + - * /, using base, quantity and length. For example, base * 0.1 + length * 2. The result is the extra price per item; saved choice extras are additional.

For example, with catalog base €20 and three characters, base * 0.1 + length * 2 adds €8 per item: two items total €56 before applicable tax and discounts.

Negative, invalid or non-finite calculated prices are rejected. Avoid a formula that can divide by zero. Test several quantities and inputs rather than checking only the initial example.

Taxes and coupons on option prices

Option charges use the same tax basis as the product catalog price. WooCommerce calculates the applicable product taxes. A percentage option uses the catalog unit price before cart discounts; it is not calculated from the cart total. Ordinary percentage coupons discount the configured product price including its option charges.

For example, three items at €20 plus a €10 setup charge once per line give €70 before tax when catalog prices exclude tax. With a 20% tax rate the total is €84. A 10% coupon reduces the taxable amount to €63 and tax to €12.60, giving €75.60. If the catalog instead includes that tax, the same configured prices give €70 including tax, or €63 after the coupon (including €10.50 tax).

Once-per-line charges are shared across the quantity for WooCommerce calculation; rounding follows WooCommerce. The tested example €19.99 × 3 plus €1 setup gives €60.97 including tax in the tax-inclusive configuration. Test the final checkout total for your actual tax locations, exemptions and rounding settings. The candidate tests cover a single noncompound 20% rate; they do not certify every tax regime or currency.

Using options with HS Min/Max Quantities

Quantity rules count physical product units, not the number of selected options. Two products priced at €20 with €5 options each still count as two units and produce €50. A multiples-of-two rule rejects three units even though their price can be calculated.

Amount rules include option charges in the evaluated product amount. With a 10% coupon, €50 becomes €45: a €47 minimum passes on the before-coupon basis and fails on the after-coupon basis. Choose the basis intentionally so the customer understands why a coupon can leave the order below the minimum. The before-Dynamic-Pricing basis is a separate setting; this particular coupon example has no active pricing promotion.

With HS Dynamic Pricing & Discount Rules active, percentage promotions currently include option charges. For two €20 products with €5 options each, the configured amount is €50. A 20% promotion reduces it to €40; an additional 10% coupon, when the promotion permits combining coupons, reduces it to €36. Min/Max evaluates €50 on the before-pricing basis, €40 before coupons, and €36 after coupons in this example. Excluding option charges from the promotion is not an available policy in this candidate.

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