first step towards financial security is taking control of your finances. Money management is an art which includes saving the right amounts and investing in the right INSTRUMENTS. However, there are several factors such as inflation and time that lower the value of money. Therefore, it is necessary to learn how to calculate the worth of one's investments.Several financial planning CALCULATORS are available on the web. However, it is also important to know some basic formulae that you can use to do your own calculations. GIVEN below are 10 such formulae that everyone should know. 1. Compound Interest You may have heard financial experts/advisors extol the power of compounding. Albert Einstein, in fact, called compounding "the greatest mathematical discovery of all time".Compounding is the process of earning interest on principal as well as accumulated interest. The longer the duration of the investment, the greater is the potential for gaining from compounding, which makes it a very powerful tool in finance.The formula isFormula: A = P * (1+r/t) ^ (nt)WhereA = amount after time tP = principal amount (your initial investment)r = annual interest rate (divide the number by 100)t = number of yearsn = number of times the interest is compounded per yearEXAMPLESuppose you intend to invest Rs 1,00,000 for 10 years at an interest rate of 10 per cent and the compounding is annual.The total amount you will receive after 10 years will be= 1,00,000(1+0.1) ^10 = 2,59,374.25This shows that the interest earned over 10 years is Rs 1,59,374.25