UCL Great Ormond Street Institute of Child Health


Great Ormond Street Institute of Child Health


Sample Size Estimation and Power Calculations with Excel

29 January 2024, 9:30 am–5:00 pm

This course gives the basics of sample size estimation. It will be of use to those embarking on a research project and who are perhaps trying to complete ethics and grant application forms. Both precision and power estimation approaches are covered.

Event Information

Open to







Centre for Applied Statistics Courses

Book Now (Hybrid)

NOTE: This course will be delivered in hybrid mode, i.e. the in-person lecture will be transmitted live on zoom. The face-to-face part of the hybrid courses will go ahead conditional on at least 5 participants registering for this mode of delivery. Few classes may be delivered exclusively online, so please check under the Future dates tab for clarification. The online part of the class will be supported by its own dedicated teaching staff (along with the lead lecturer), therefore participants can expect the same level of group and individual support as the face-to-face class. You will be able to choose your preferred mode of attendance (face-to-face or online) during registration


The concepts of sample size estimation are introduced, including when and why this might be necessary. Formulae are presented and discussed. An accompanying weblink is introduced which hosts excel sheets pre-programmed to facilitate use of the formulae. In the first part of the course, the precision-based approach to sample size estimation is introduced, whereby the numbers are selected to produce a confidence interval for the relevant estimate with a specified width. In the second part, we progress to the more traditional power calculations that aim to give the sample required to determine a specified difference with selected power and significance levels. All terminology will be explained as it is introduced in the sessions.

Sample size estimation is discussed for the following measurements:

  • Means
  • Proportions/ percentages
  • Rates

Notes and spreadsheets are also provided to cover the following, which will be discussed if time permits:

  • Time to event data
  • Measures of agreement
  • Percentiles

Everyone wishing to attend should ensure Microsoft Excel (or alternative compatible software) is installed.


Course fees

External Delegates (Non UCL)£175.00
UCL Staff and Students £87.50 
UCL Alumni£87.50
Staff and Doctoral Students from ICH/GOSHFREE †

* Valid UCL email address and/or UCL alumni number required upon registration. Please note, this category does not include hospital staff unless you hold an official contract with the university.

† Limited free spaces available. If there are no free places remaining, Staff and Doctoral Students from ICH/GOSH can still register at the UCL rate.

Cancellations: Cancellation Policy 

Future Dates

29th of January 2024

9.30am - 5.00pm

Book Now
^We recommend logging in 10 minutes prior to the scheduled start time to access materials and ensure the course can start promptly.
Future Dates (evening)
TBC5.00pm-8.15pm^Subscribe to general mailing list
^We recommend logging in 10 minutes prior to the scheduled start time to access materials and ensure the course can start promptly at 9.30am.

“Excellent as always. This is my 6th course and all were extremely useful and relevant"

"Very good course and exactly what I needed. Course material is very good though and will be a helpful reminder in the future.”

"Really well paced course, very useful being provided with the excel spreadsheets, friendly and experienced staff, highly recommend all of these courses!”

"I really like the courses because they are well explained and the material is clear.”

"I really enjoyed the training session. I can say that the course is timely because I am developing a proposal where I would apply the knowledge gained in this training to calculate my sample size for the study. Keep it up”