Facebook and Instagram budget calculator built on how Meta actually prices

Google charges per click, so a plan needs a CPC and a conversion rate. Meta charges per thousand impressions, so the click price is itself a result: CPM divided by a thousand times the click-through rate. A €12 CPM at a 1.4 percent CTR is a €0.86 click; the same CPM at 0.9 percent is €1.33. That is why the planner asks for CPM, CTR and conversion rate, and why the campaign objective matters so much: an instant lead form converts a third of its clicks because nobody leaves the app, a landing page converts a twelfth, and a booked-call flow a twentieth.

The presets load typical values per objective for European and North American lead generation. Overwrite them with your own account's numbers from Ads Manager the moment you have them; the presets exist to give a first order of magnitude, not a forecast.

Start from a goal when you know the leads sales needs; the planner returns the monthly budget and the daily figure to set at the campaign or ad set level. Start from a budget when the number is fixed; the planner returns the leads, impressions and clicks it buys. The what-if row shows what half, one and a half and twice the budget would do, linearly, which is right for planning and optimistic in practice: scaling into colder audiences raises the CPM and lowers the conversion rate at the same time.

Every forecast above assumes the conversion is tracked. On Meta it often is not. Since Apple's App Tracking Transparency prompt, Safari's cookie limits and consent banners, the pixel observes roughly 50 to 70 percent of the conversions that actually happen. Ads Manager will report 100 to 140 leads for a campaign that produced 200, the reported cost per lead will read up to twice the real one, and Advantage+ will be learning from the visible half, which skews away from iPhone users, Safari users and Europeans who decline cookies.

The planner's closing line shows what that means for your forecast. The fix is the Conversions API fed from your CRM rather than from the same browser events: send the leads the CRM actually received, matched to the fbclid, with the deal stage attached, and the platform sees the whole picture and bids on customers instead of form fills.