Question

Does anyone know the formula to calculate IRR?

Answer 1

guess an interest value if npv is way above zero ......guess another value of i if npv is below zero the answer for the irr is between the values of the "i's"....

Answer 2

an interest rate which gives npv=0 is irr.\[\sum_{1}^{n} (income i/(1+r)^i)-\sum_{1}^{m}(expenditure k /(1+r)^k)\]

Answer 3

the value of r for which this is 0 is irr