I am aware that you are in India, but maybe if you were to use a search engine you could find some free software that will do basic stuff.
I know that Home Depot used to give out free Estimating Software CD's at their Pro Desk Counter that would probably suffice. What it would do is calculate what your labor hours should be per item. So a light switch would be .5 hours and you would enter what the labor rate was. Once all of the materials were totaled it would add the labor to the Home Depot materials costs and then allow you to enter any extras that you may want (such as mark-ups).
I picked up a couple copies a few years back (when I used to do Handyman work). It was well worth a few bucks, and since it was free software I enjoyed it even more.
I did a quick search of the HD web site but couldn't find a link to download the software.