Estimate time to review a peer document.
Peer review time is reading plus writing plus a summary judgement. Depth is the multiplier that matters: a light structural read is half a standard review, while verifying analyses and checking references nearly doubles it. Each substantive comment costs a couple of minutes to phrase constructively, and a summary recommendation adds a fixed half hour of thinking that cannot be rushed.
Reading effort
Reading minutes = pages x minutes per page x depth factor
Total effort
Total hours = (reading minutes + comments x 2.5 + 35 minutes summary) / 60
Surveys consistently report four to six hours for a standard article review, which matches this calculation for a typical manuscript at standard depth.
That is deep review and is not always expected. Reviewers are generally asked to assess whether the method is appropriate and the conclusions supported, flagging anything that looks wrong rather than reproducing the analysis.