To compute monthly instalments of a loan, we use the built-in PMT (Payment) function available in Excel and other financial software.
Syntax of PMT function:
\[
\text{PMT}(rate, nper, pv, [fv], [type])
\]
Parameters:
\begin{itemize}
\item rate – The interest rate for each period. If annual rate is 12% and payments are monthly, rate = 12%/12 = 1% or 0.01.
\item nper – Total number of payment periods. For a 5-year loan with monthly payments, nper = 5 × 12 = 60.
\item pv – Present value or principal amount of the loan.
\item fv – (Optional) Future value. If omitted, it is assumed to be 0.
\item type – (Optional) 0 or 1, where 0 = payment at end of period (default), 1 = payment at beginning.
\end{itemize}
Example:
For a loan of \rupee5,00,000 at 12% annual interest for 5 years paid monthly, the formula would be:
\[
\text{=PMT}(0.01, 60, 500000)
\]
This returns the fixed monthly EMI amount to be paid.