# Sample Size Calculation with RPV

#### Kathy

##### New Member
Can you calculate a sample size using revenue per visit (RPV)? If so, are there any online calculators, Excel formulas or tools that can be used for this? I have tools for calculating significance with revenue, but have not seen anything for sample size. Thank you!

#### noetsi

##### No cake for spunky
Sample sizes have to assume a distribution I believe and are normally involved with test statistics. Like a f or t test. I have not heard of RVP. Does it have a known distribution?

#### hlsmith

##### Less is more. Stay pure. Stay poor.
Moreover, what question do you need a sample size for? Please write out that question so we can understand you question. You can have a sample size calculation for a non-test. For example an estimate which excludes a constant or has a desired level of precision. I am also not familiar with RPV.

#### Kathy

##### New Member
hlsmith I run tests on an ecommerce website and I calculate my sample based on order conversion rates (CVR) now, however, conversion rate is not our primary metric. We are more interested in driving revenue per visit (RPV). Below is a specific example:

Objective: Determine the impact of the new feature added to the page in the test experience
Visits Revenue RPV Orders CVR
Control Default page experience 500,000 $3,500,000$7.00 250,000 0.50%
Test New feature added to the page 500,000 $3,525,000$7.05 275,000 0.55%

80% Power
95% Confidence

What's the best way to calculate the sample size needed if RPV is the metric you want to optimize for?