Description
Sample Size Calculation and Power Analysis
Ethics committees, funders and journal reviewers all expect a justified sample size. We calculate it for your specific design and outcome, test realistic scenarios and write the justification paragraph you need for the protocol, grant or methods section.
What you receive
- Power analysis matched to your design and primary outcome
- Effect size estimation from pilot data or published literature
- Several scenarios (effect size, power, alpha, attrition)
- Methods text with formulae or software stated
- Supporting references for the assumptions used
How it works
- Tell us the design, primary outcome and any pilot or published estimates
- We confirm assumptions with you
- Calculations are run and cross-checked
- You receive the report and ready-to-use justification text
Standards we follow
Calculations follow CONSORT, SPIRIT or STROBE expectations for reporting sample size, and are documented so a reviewer can reproduce them.
Turnaround and price
2–3 business days. Price $150.
Frequently asked questions
I have no pilot data. Can you still calculate it?
Yes. We derive plausible effect sizes from comparable published studies and show how the sample size changes across them.
Which software do you use?
R and G*Power, with the exact settings reported.
Questions before ordering? Contact our team or request a quote.
