Quantity from guest count: tiered quantities on a product

Some products scale with the size of the event: standing tables, glasses, napkins, floral decoration. Instead of estimating the quantity for every event, you set a quantity rule on the product — the line item then takes its quantity from the guest count.

Where the rule lives

1. Open Products and the product you want.
2. Scroll to the Price & stock section in the product editor.
3. In the Quantity from guest count block, tick Calculate quantity from guest count.

The block only appears once the product has been saved — before the first save there is no product for the rule to hang on.

The fields

• Units per tier — what you need per tier, e.g. 1 for one standing table. Fractions work too: 0.5 means half a unit per guest.
• per number of guests — the tier size, e.g. 10 for “per 10 guests”. For “0.5 per guest” you enter 1 here.
• Rounding — Round up (the default: any started group of guests counts in full), Round down, Commercial rounding or Do not round (then two decimals stay, e.g. 37.5 bottles).
• Only from guest count — optional. Below it the rule does not apply: the line item keeps the quantity you typed (it never drops to 0).
• Minimum quantity — optional, also applies when the event has no guest count.
• Maximum quantity — optional, caps the result.

The Sample in the block calculates with the example guest count you enter next to it, so you see what the rule produces without creating a document. If the rule asks for more at that guest count than the product’s maximum quantity allows, a note appears below it — on the booking page the quantity then stays at the maximum.

What the rule does on a line item

• Take the product into a quote, an invoice, a delivery note or an event’s bookings and the new line item carries the calculated quantity. Sample: rule “1 per 10 guests, at least 2”, event with 73 guests → quantity 8.
• The line item shows a small hint such as “1 per 10 guests → 8”. It tells you the number comes from the rule, not from a typo.
• If the guest count of a draft changes, these line items recalculate automatically. Sent or accepted documents ask, as they always have.

When you change the quantity yourself

As soon as you type a quantity into a rule line item yourself, it detaches from the rule: it then stays put even if the guest count changes later. Line items without a rule and existing documents behave exactly as before.

On the booking page

When a guest enters their guest count on your booking page, products with a rule get the same quantity in the cart and in the booking — so the number you check is the number that ends up on the document. There the rule acts as a floor: the guest can raise the quantity but not go below it. Products without a rule, ticket pages without a guest count, and “Per guest” as well as flat-rate products calculate as before. If the rule asks for more than the product’s maximum quantity, the floor stops at the maximum — the product stays bookable instead of being rejected for exceeding the maximum.

Apply the rule again

If you typed the quantity of a line item yourself, it shows “Quantity set by you — 1 per 10 guests would be 8” with the Apply rule again button. One click brings the quantity back from the current product rule and the guest count; the line item follows the guest count again from then on. The button only exists on line items where you set the quantity yourself — existing documents stay unchanged.

Import and export

You can also maintain the rule via Excel/CSV import. The columns are Quantity per guests, Per number of guests, Rounding, Rule from guest count, Rule minimum quantity and Rule maximum quantity; “Quantity per guests” and “Per number of guests” must both be filled, otherwise the rule stays empty and the import tells you. The product export writes the same six columns, so a downloaded file can be imported back unchanged. An import sets rules, it never deletes them: empty cells mean “no statement”. If a product already has a different rule, it stays unless you pick Overwrite existing values.

Special cases

“Per guest” products. With the billing models Per guest and Per guest and hour, the guest count already has its own column on the line item. There the rule is the share per guest (e.g. 0.5 bottles), never the total — otherwise the guest count would be counted twice.

Flat-rate products. Flat rates always have quantity 1. A quantity rule would change nothing there, so the block is locked for flat-rate products.

Event without a guest count. Then the rule’s minimum applies. Without a minimum the quantity is 1.

Removing the rule

Untick Calculate quantity from guest count — the fields disappear, but the saved rule stays. Then click Remove rule so the product calculates like a product without a rule again. Line items already created keep their quantity.