Math Geek.... Power Analysis and Sample size

[SaltERedneck]

Anyone know about sample size and power analysis. I am writing a research paper and need to get a power analysis of 0.80. I would like my sample size to be large enough to yield this data. Would a sample size of n = 50 (group 1 = 25, group 2 = 25) provide this? This study will be reviewed by the IRB committee here in LC for approval. Realistically a sample size of 50 is unlikely in the sample i am researching (SQ insulin vs. IV insulin in the management of uncomplicated diabetic ketoacidosis) because this would require a year or so of data collection. Or if anyone can find a website that does the calculation I would be grateful.

Group 1 = IV insulin
Group 2 = SQ insulin

T test would be the given formula.