Campaign Inputs
Use the grid below for data entry. The form uses three columns on large screens, two on tablets, and one on mobile.
Example Data Table
This sample shows how reach typically rises with impressions while marginal audience gain slows as duplication increases.
| Scenario | Audience | Impressions | CPM ($) | Response Factor | Shape | Estimated Reach (%) |
|---|---|---|---|---|---|---|
| Starter Flight | 1,000,000 | 500,000 | 8.50 | 0.85 | 1.15 | 29.80 |
| Awareness Push | 1,000,000 | 1,250,000 | 8.50 | 0.85 | 1.15 | 55.69 |
| Balanced Plan | 1,000,000 | 2,500,000 | 8.50 | 0.85 | 1.15 | 78.11 |
| Heavy Burst | 1,000,000 | 3,750,000 | 8.50 | 0.85 | 1.15 | 89.76 |
| Saturation Zone | 1,000,000 | 5,000,000 | 8.50 | 0.85 | 1.15 | 95.35 |
Formula Used
- Average Frequency in Universe:
f = Impressions / Audience - Negative Exponential Reach:
Reach Ratio = 1 - e-λf - Weibull Reach:
Reach Ratio = 1 - e-λfβ - Reached People:
Reached = Audience × Reach Ratio - Average Frequency Among Reached:
Freq(Reached) = Impressions / Reached People - Campaign Cost:
Cost = (Impressions / 1000) × CPM - Effective Reach n+: estimated with a Poisson exposure model using the chosen exposure threshold.
- Target Reach Impressions: derived by inverting the selected response curve for the entered target percentage.
How to Use This Calculator
- Enter the total target audience for the campaign.
- Add planned impressions and your CPM value.
- Choose a response factor and curve shape based on observed duplication.
- Select either Weibull saturation or negative exponential behavior.
- Set the graph range and number of curve points.
- Choose an effective frequency threshold such as 3+ exposures.
- Enter a target reach percentage for planning guidance.
- Press calculate to view summary metrics, the plotted curve, and downloadable results.
Frequently Asked Questions
1) What does a reach curve show?
A reach curve shows how many unique people are likely to be reached as impressions rise. It also helps reveal duplication and diminishing marginal audience gain.
2) Why does reach slow down at higher impression levels?
As delivery increases, more impressions go to people already exposed. That duplication raises frequency but adds fewer new people, so the curve flattens.
3) What is the response factor in this calculator?
The response factor controls how quickly the reach curve rises. Higher values imply faster audience coverage with the same average frequency.
4) When should I use the Weibull model?
Use the Weibull option when you want more control over curve shape. It is useful when early growth or late saturation differs from a simple exponential pattern.
5) What is effective reach?
Effective reach estimates the share of the audience exposed at least a chosen number of times, such as 3+. It is often more actionable than raw unique reach alone.
6) How is target reach converted into required impressions?
The calculator reverses the selected reach formula. It solves for the average frequency needed to hit the target, then multiplies by audience size.
7) Can I use this for budget planning?
Yes. Since the calculator combines impressions and CPM, it estimates spend, cost per reached thousand, and budget needed to hit a target reach level.
8) Are these outputs exact forecasts?
No. They are model-based estimates. Real delivery depends on channel mix, placement quality, auction conditions, targeting breadth, and frequency controls.