Count the test cells a fixed learning budget can actually fund
A testing plan can multiply concepts, variants and audiences until each cell receives too little of its intended allocation. A reproducible illustrative example with editable inputs and explicit limits.
A testing plan can multiply concepts, variants and audiences until each cell receives too little of its intended allocation. This worksheet exposes that multiplication before launch. The per-cell amount is a planning assumption supplied by the reader, not a platform learning threshold.
Define the calculation before using it
Enter total budget, concept count, variants per concept and intended spend per cell. Calculate cells and required spend, then compare them with the envelope. Keep production outside the media budget only if the approved plan genuinely funds it separately. Record the evidence question before choosing the cell count.
Work through the synthetic example
With 12,000 available, four concepts, three variants each and 1,200 per cell, the plan needs 14,400. The 2,400 shortfall requires a scope decision. Quietly thinning every cell while retaining the original evidence promise can leave the experiment unable to answer the question it was commissioned to resolve.
| Output | Worked-example result |
|---|---|
| Planned cells | 12.0000 |
| Required media spend | 14400.0000 |
| Budget headroom | -2400.0000 |
Use the artifact and preserve its assumptions
Open the editable calculator to change the inputs and inspect the sensitivity view. The CSV records synthetic inputs and expected outputs; the JSON fixture keeps the equations available for reproduction. These calculations have been checked against the stated example. No measured campaign data is included.
The sensitivity rows vary only variants by 20% below and above the entered value. They are scenarios, not confidence limits or a forecast distribution. A row outside the model’s constraints is labelled rather than turned into a plausible-looking result. Save the chosen inputs with the decision so another reader can distinguish a changed assumption from a changed formula.
Evidence and limits
Google distinguishes average daily budgets from campaign total budgets. This planning worksheet does not itself set a platform limit; verify the campaign’s actual budget mechanism before translating a plan into account settings. See Budgets overview, especially “Average daily budgets and spending limits; Other types of budgets”.
A funded cell is not necessarily statistically useful. Required sample depends on outcome rates, variance, design and decision precision, not an arbitrary currency allocation.
Background: Annual and quarterly UA budget planning and A Q4 UA Budget Planning Checklist Before the Rush. These existing articles provide context; the present calculation does not verify every archived claim.
