I make websites and I want to provide financing for those who can't afford the full amount up front. The only payment plan I will have is 12 months. The interest rate will be 18%. Small monthly payments will benefit them more than me so I have to make it worth my while.
I understand taking the 18% and dividing by 12 months to get the monthly interest rate of .015
But how do you calculate the monthly payments and how much goes toward the interest and the principle each month?
The online calculators give me this based on $1500 - monthly payments of $137.52 and a total interest amount of $150.24.
How did they come up with $150.24 interest and the monthly rate?