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Incidence rate calculator
Screener starts, screen outs and drop offs behind your target completes, and why it is the number that sets B2B sample cost.
An incidence rate calculator converts your target number of completes into the number of screener starts a supplier has to generate. Enter target completes, the expected incidence rate, drop off and over quota rate, and it returns starts, screen outs and drop offs. At 18% incidence, 300 completes takes roughly 2,000 starts.
Inputs
Screener starts required
2,064
starts to reach 300 completes at 18% incidence
- Qualified starts
- 372
- Screen outs
- 1,692
- Over quota
- 19
- Drop offs
- 53
- Completes
- 300
Every screen out is a respondent who was invited, started, and was paid nothing. That is where low incidence cost comes from.
How the incidence rate calculator works
starts = qualified / incidence
screen outs = starts − qualified
Incidence is the share of people who start the screener and qualify. Drop off is the share of qualified respondents who do not reach the end. Over quota is the share of qualified respondents who are turned away because their cell is full. Each one multiplies the number of starts you need.
Why incidence drives B2B sample cost
These are the rates a vendor quotes against broad business supply, and they are what makes low incidence audiences expensive: every start costs money whether or not the person qualifies. Targeting from a profiled panel lifts the yield well above these figures. What it cannot change is the size of the qualified pool, which is what actually caps a C-suite study.
At 18% incidence, reaching 300 completes takes about 2,000 screener starts. At 6% incidence, the C-suite figure, even 100 completes takes more than 1,900. Every one of those starts costs the supplier something, whether or not the respondent qualifies, and the cost per complete has to carry all of them. This is the whole reason a verified C-suite complete costs three times an IT decision maker complete. The cost per complete estimator turns this into a price.
The incidence trap
A vendor who quotes 30% incidence on an audience where an estimated qualification rate we believe is 12% is not reaching more people. They are qualifying people who should have screened out. The field will either come in slow with a revised price, or it will come in on time with data from respondents who do not hold the role. Ask any vendor what their incidence assumption is built on, and compare it to published figures.
Incidence rate calculator: frequently asked questions
What is incidence rate in survey research?
The percentage of people who start a screener and qualify for the survey. An 18% incidence means 18 of every 100 starts qualify. It is the single biggest driver of B2B sample cost because every start that does not qualify still costs something to generate.
What is a typical incidence rate for B2B surveys?
It varies by audience. Small business owners run around 34% in a business targeted sample, IT decision makers around 18%, finance leaders 12%, C-suite at 1,000+ employees around 6%. Narrow screens push every one of these down.
What drop off rate should I assume?
Ten to twenty percent of qualified respondents for a 12 to 15 minute B2B interview. It rises sharply beyond 20 minutes and for senior audiences. If a vendor assumes zero drop off, the field estimate is optimistic.
How do quotas affect the number of starts?
Quotas turn away qualified respondents whose cell is full. Tight quotas on rare cells can push over quota rates above 20%, which is why very specific quota designs raise both field time and cost.
Send the spec. Get real numbers back.
Audience, market, target n, expected interview length. Feasibility the same business day for standard audiences, with reachable counts, an estimated qualification rate we believe and a quoted cost per complete that stays fixed for the agreed brief.