Smart Bidding budget calculator

Why there is a floor at all

Smart Bidding sets a bid for every auction from what it has learned about which clicks turn into conversions. Learning needs examples. Under roughly 30 conversions a month the strategy never accumulates enough of them to tell one kind of lead from another, so the bids it sets stay close to guesses.

This is the part that catches people out, because nothing fails visibly. The campaign runs, leads arrive, the reports fill in. What does not happen is improvement, and three months later the conclusion drawn is usually that value-based bidding does not work, when what actually happened is that it never had enough to work with.

The arithmetic, in full

Your cost per lead multiplied by 30 is the monthly spend. Divided by 30.44, the days in an average month, it is the daily budget. There is nothing else in it, which is deliberate: a budget recommendation you cannot check on the back of an envelope is a recommendation you should not act on.

What the arithmetic cannot do is predict. It uses today's cost per lead, and your cost per lead changes as soon as the bidding changes, which is the reason for doing any of this. Read the result as the floor to start above.

If the floor is out of reach

Raising the budget is the obvious answer and usually the worst one. Three of these four cost nothing.

• Merge campaigns into one bid strategy

  Five campaigns at eight conversions a month each are five strategies that never learn. The same spend behind one is forty, which does. This is free, and it is the single most common fix.

• Use a portfolio bid strategy

  Keeps campaigns separate for reporting and budget while they share one learning set. The right answer when the campaigns genuinely need to stay apart.

• Widen the match types and audiences

  Tight targeting starves the strategy of examples. Broadening it costs nothing and is easier to undo than a budget increase.

• Count the conversions you already have

  Leads reaching your CRM without a Google click ID count toward nothing, because Google cannot attribute them. Fixing capture can clear the floor without any extra spend at all.

Volume is necessary, not sufficient

Clearing the floor gets the strategy enough examples. It does not give it anything to sort them by. Value-based bidding works on the difference between what one lead is worth and what the next one is worth, so a feed where every lead carries the same value makes Maximize conversion value arithmetically identical to Maximize conversions: the same ranking, the same spend, the same leads.

Both halves are checkable against your own data. The diagnostic reads a CRM export in your browser and reports your real volume, the spread between your leads and whether Google can match them at all. The assessment is ten questions and takes two minutes if you would rather not upload anything yet.

Questions

Why 30 conversions a month?

It is the figure Google publishes as the point where value-based Smart Bidding has enough examples to work with. Below it the strategy is not wrong so much as under-informed: it never sees enough outcomes to separate a good lead from a bad one, so bidding stays about as noisy as it was before, whatever values you send.

Does spending this much guarantee 30 conversions?

No, and the calculator does not claim it. It multiplies your current cost per lead by 30. Your cost per lead moves once bidding changes, which is the whole point of changing it, so treat the result as the floor to start above rather than a forecast.

Is the threshold per campaign or per account?

Per bid strategy. A campaign with its own strategy needs its own volume, which is why splitting one healthy campaign into five themed ones is the commonest way an account falls below the floor without anyone spending a penny less.

What counts as a conversion for this?

The conversion actions the campaign is optimising toward. If you import offline lead values, those imported conversions count once Google is attributing them, which is also why match rate matters: a lead Google cannot join back to a click never counts toward anything.

What if I cannot afford the floor?

Consolidate before you spend. Fewer campaigns sharing one bid strategy, or a portfolio strategy across several, pools the same spend into one learning set. Broader targeting and longer conversion windows both help too. Raising the budget is the last option, not the first.

Does this apply to tROAS and Maximize conversion value?

Yes, and more so. Those strategies learn from the spread between one conversion's value and the next, so they need both the volume and enough variety in the values. Volume without variation gives them nothing to sort.