In order to see how much you need to repay every month on your mortgage the easiest way would be to use a repayment mortgage calculator.
The total that the mortgage calculator gives you will only be the minimum payment you need to pay.
This payment will change as your mortgage amount, the interest rates and the mortgage term changes.
Although this calculation can give you an indication of what you need to pay, it doesn't include all costs.
You might also have other costs that could be added to the total mortgage amount.
Otherwise you have to pay it from your own pocket before you get a mortgage.
There are also extra monthly costs that could include but are not limited to the following:

• Monthly bank charges
• Monthly home insurance costs
• Attorney fees to get the property transferred to your name
• Mortgage costs in able to get a new mortgage
• Transfer duty costs

Except for those charges that are associated with the mortgage, you will most probably also have other costs after buying the property that could include the following:

• Repair costs when things in and around the house breaks
• Municipal costs including water and electricity
• Property taxes
• Maintenance costs on the property

So as you can see you shouldn't only look at the answer you get from a mortgage calculator in order to determine if you can afford a certain property.
Make sure that you have enough money left after the mortgage repayment to afford the other costs that might appear with time.
If you don't make provision for these extra costs you could very quickly run into big problems.
Rather get a more affordable property and be sure that you will be able to also afford the unplanned costs.
Then you should easily be able to afford the repayments and will be able to pay extra to finish paying early.