Sample size for a one sample t-test

This [attachment:onesamp.xls spreadsheet] computes the total sample size for a one sample t-test with given power.

This can also be done using this [http://www.stat.ubc.ca/~rollin/stats/ssize/n1.html on-line calculator] which use a slightly more liberal criterion (normal quantiles as opposed to t quantiles) for sample size evaluation than the above spreadsheet.