Premium Plans & Stripe Billing

The site is free by default, with a generous daily calculation limit, which is great for traffic. You can optionally turn on a Premium membership to earn from that traffic.

What Premium offers visitors

A Premium membership removes ads and the daily calculation limit, and saves a member's calculation history. The full result of every calculator is always free, so Premium adds convenience and removes limits rather than unlocking a "better" answer.

Setting it up

• Add your Stripe keys in Settings.
• Create one or more plans under Premium Plans, with a price, interval and features.
• Use the single toggle to turn the whole premium surface on or off. Off means a completely free site with no pricing shown.

Reliable by design

Stripe webhooks are signature-verified and idempotent, so a payment or subscription is never double-counted, and your revenue figures stay accurate.

Refund Policy page

When premium billing is on, the site adds a ready Refund Policy page at /refund and links it in the footer's Legal column. Edit its wording under Admin, Dynamic Pages. It appears only while payments are enabled and hides automatically if you turn them off, so a free site never shows a refund page it does not need.