Reverse Formula with PMT function in Equation?

Hello,

This is similar to my previous posting, but a tad more difficult (at least for me).
I need the formula to solve for the interest rate. Here is the existing equation to reverse:

=C10/(PMT(E39/12,J2*J3,-C2)*12 which yields a value of 1.53

C10 =134,900
E39 =5.50%
J2 =25 Years
J3 =12 Pmts per year
C2 =1,200,000

I need to know the formula to solve for the interest rate if the value is 1 instead of 1.53.
It's seems to be more difficult since there is PMT formula in the middle of the equation so it's difficult for me to do the algebra.

Thank you so much

Try using the RATE function.

I did. I need to solve for the interest rate. In the example 5.50% is the interest rate. The formula I gave gives a value of 1.53, I need to know the % if the value is 1.00.

Ursul, I need more info than that. I have racked my brain. To make things easier, I need to know what excel does with the PMT function so I can just make the whole thing a math formula and then work backwards making the interest rate the variable to solve for.

Rick, have you try using F1 and finding the RATE function or the PMT function and see what it says - they have very good explanations.

LOL, ok guys for all you algebra fans I figured out a straightforward equation:

=C10/((C2*(E39/12))/(1-(1+(E39/12))^(-J2*J3))*12) which yields 1.53

Using the following:
C10 =134,900
E39 =5.50%
J2 =25 Years
J3 =12 Pmts per year
C2 =1,200,000

I need to revamp the equation to solve for the interest rate if the number is 1.00 not 1.53.

Ok, I have a formula that seems to be very close:

=ROUND(((RATE(J2*J3,-1,C2)*(J2*J3))/-100),15)

This formula results in 10.4596984615322% Which is right on target; however, the values in J2, J3, and C2 will change with each project and then the percentage does not come close to the right answer. Any suggestions? I know I'm making progress.