Calculate Content Validity Ratio (CVR) from Ne and total experts, or solve for either value when any two survey inputs are fully known.

Content Validity Ratio Calculator

Enter any 2 values to calculate the missing variable. Note: Ne and N are counts (whole numbers) with 0 ≤ Ne ≤ N, and CVR is between -1 and 1.


Related Calculators

Content Validity Ratio Formula

The content validity ratio, or CVR, measures how strongly a panel of experts agrees that an item is essential. It is based on the number of experts who rate the item as essential compared with the total number of experts.

CVR = (Nₑ - (N / 2)) / (N / 2)
Nₑ = CVR * (N / 2) + (N / 2)
N = (2 * Nₑ) / (CVR + 1)
  • CVR = content validity ratio, ranging from -1 to 1
  • Ne = number of experts who rate the item as essential
  • N = total number of experts on the panel

The calculator can solve for any one missing value when you enter the other two:

  • Calculate CVR: Enter Ne and N to find the content validity ratio.
  • Calculate Ne: Enter CVR and N to find how many experts must have rated the item as essential.
  • Calculate N: Enter Ne and CVR to estimate the total number of experts implied by those values.

In practical use, Ne and N are counts, so they should be whole numbers. If a rearranged calculation gives a decimal expert count, that result is mathematically valid but may not describe a possible real panel without rounding or changing the inputs.

CVR Values by Expert Agreement

CVR increases as more experts rate an item as essential. A CVR of 0 means exactly half of the experts rated the item as essential.

Expert agreement Relationship between Ne and N CVR meaning
No experts say essential Ne = 0 CVR = -1
Fewer than half say essential Ne < N / 2 Negative CVR
Exactly half say essential Ne = N / 2 CVR = 0
More than half say essential Ne > N / 2 Positive CVR
All experts say essential Ne = N CVR = 1

Example CVR Results for Common Panel Sizes

Total experts, N Experts rating essential, Ne CVR
5 4 0.6000
8 6 0.5000
10 8 0.6000
12 9 0.5000
15 12 0.6000

Content Validity Ratio Examples

Example 1: Calculate CVR

Suppose 8 out of 10 experts rate an item as essential.

CVR = (8 - (10 / 2)) / (10 / 2)
CVR = (8 - 5) / 5 = 0.6

The content validity ratio is 0.6000.

Example 2: Calculate Ne

Suppose the total panel size is 12 experts and the CVR is 0.5.

Nₑ = 0.5 * (12 / 2) + (12 / 2)
Nₑ = 0.5 * 6 + 6 = 9

The number of experts rating the item as essential is 9.

Content Validity Ratio FAQ

What does a negative CVR mean?

A negative CVR means fewer than half of the experts rated the item as essential. For example, if 3 out of 10 experts rate an item as essential, the CVR is -0.4. That indicates weak expert support for the item as essential.

Can CVR be greater than 1 or less than -1?

No. CVR is limited to the range from -1 to 1. A value of -1 means no experts rated the item as essential. A value of 1 means every expert rated the item as essential.

Why can calculating N return a decimal?

The formula for solving total experts is algebraic, so it can return a decimal if the entered CVR and Ne do not match a possible whole-number panel. Since experts are counted as people, a real panel size must be a whole number. If the result is decimal, check whether the CVR was rounded before entry.