Commercial property rental payments are the sum of the Net Rent, the Additional Rent (sometimes referred to as the T.M.I.) and the applicable G.S.T. Your monthly property rental rate would be calculated by multiplying your rentable square footage by the yearly net rental rate, and then dividing the result by 12. A similar calculation is done for the Additional Rent.
For example, if you have 1000 rentable square feet, and the annual net rent per square foot is $6.00, 1000 x $6.00 = $6000. $6000 / 12 = $500.00 a month in rent.
Similarly, if the annual additional rent per square foot is $3.42, 1000 x $3.42 = $3,420. $3,420 / 12 = $285.00 a month in rent.
The monthly property rent payable would be the sum of the net rent and additional rent ($785.00 in the example above). 5% G.S.T. is then added for a total monthly property rental in the amount of $824.25.