Dear Querist,
I assume your query is only on TDS on Salaries. (Do you know TDS is also on various other payments made by your organisation like interest, rent, professional fees, payment to contractors and sub-contractors, transports, commission etc)
It is not only how to calculate, but also how to pay and how to file returns of TDS. You may be able to calculate with the help of the given link, in normal cases; but please appreciate that there are types and types of issues. e.g. Someone joins in between and wants you to include his previous employer's salary in the return or some one has some capital gains or someone has some other income / house property/ties and so on.
if you are uninitiated at these subjects you will end up on the wrong side of the law.
Better consult your tax consultants / auditors; understand the fundamentals or hire someone who knows.
A S Bhat