Yes there are a lot of mortgage calculators on the web, so who really needs another one. The calculators I write are most often single function calculators. You can add them easily to your home screen on your mobile device for quick reference. They aren't buried deep in a site, they are the site.
When I see two calculators like the Victorian Stamp Duty Calculator and the Mortgage Repayment Calculator that are often used by people around the same time, I can then provide handy links between the calculators.
If you would like to know how much the monthly repayments on a mortgage are, give the Mortgage Repayment Calculator a shot at www.Mortgage-Repayment-Calculator.com.au.