EMI calculator is based on the following formula:
[P x R x (1+R)^N]/[(1+R)^N-1
where P stands for the loan amount or principal,
R is the interest rate per month [if the interest rate per annum is 11%, then the rate of interest will be 11/(12 x 100)],
and N is the number of monthly installments

Car loan EMI calculator is based on the above mentioned formula.