G*power is a very good free software for power analysis

http://www.gpower.hhu.de/en.html

UCLA gives some good introduction and examples on it

http://www.ats.ucla.edu/stat/gpower/indepsamps.htm

http://www.ats.ucla.edu/stat/seminars/Intro_power/default.htm

I use G*Power to compute effect sizes and to display graphically the results of power analyses.

http://www.gpower.hhu.de/

Thank you for your help...

You can use the online programs from DSS research also

https://www.dssresearch.com/KnowledgeCenter/toolkitcalculators/statisticalpowercalculators.aspx

https://www.dssresearch.com/knowledgecenter/toolkitcalculators/samplesizecalculators.aspx

Quanto also might be useful:

http://biostats.usc.edu/software

PGA:

http://dceg.cancer.gov/tools/analysis/pga

GAP package of R: 

http://cran.r-project.org/web/packages/gap/vignettes/gap.pdf 

and pbsize() function

Margaret

Thank you for your help.

Hi,

Please use DIgSILENT POwer Factory and Please see this link:

https://www.researchgate.net/post/Dear_All_is_DIgSILENT_PowerFactory_1413_a_free_or_is_demo_available_if_so_please_send_me_the_link

You can see also this link

http://www.uploadbaz.com/s5dewp9651st