I am struggling with an Excel query. I know if you want to work out the interest rate you can do =PMT(B2,B3,B1)/12 which will tell you the amount payment depending on the current value, the number of payments, the rate. I have seen somewhere a calculation where you can put in your mortgage repayments currently (capital and interest) and by changing the interest rate see what your mortgage payments can be - can anyone help me here?