It [interest] is calculated daily and charged monthly

If interest is truly "calculated daily", then the monthly rate varies based on the number of days in each month (28, 29, 30 or 31).

In that case, the only way to calculate total payments is with an amortization schedule. That also requires the loan date and the first-payment date as input.

But it is unusual for interest on loans

*per se* to be calculated daily.

I'll assume that either you misunderstand, or you do not require that degree of accuracy.

what I have [is] wrong [....] because i need to have it compound daily and charged monthly

I suspect that you mean the annual rate is a compounded rate, calculated by compounding daily.

That is common for mortgages

*per se* in EU countries, for example. It might not apply to other types of loans, in the UK for example.

In that case, instead of a monthly rate of 7.2%/12, it is (1 + 7.2%)^(1/12) - 1 or equivalently RATE(12, 0, -1, 1+7.2%).

The following assumes that.

(However, it is unusual for US loans to state a compounded annual rate. IIRC, the "Truth In Lending" regulations require a simple interest rate. In that case, the monthly rate is indeed 7.2%/12, and the daily rate is typically 7.2%/365, even for leap years, IIRC.)

what I have [is] wrong as all I've done was add the fees and charges after I had calculated the FV

It is correct for you to add fees and charges as you did. They are not amortized with the principal of the loan.

However, your use of FV applies to a savings of $100,000, in which interest is compounded. In contrast, for loans, interest declines over the term of the loan because it is based on outstanding principal, which declines with each payment.

The following is based the data in your posting #4, which differs significantly from your initial posting. (sigh)

Select or hover the cursor over cells to see formulas. In particular, the formula in G10 is:

=D9*D8*12 + SUM(D12:D13) + D14*D8*12 + D15*D8

For comparison, I show the calculaton of total interest using CUMIPMT in G12. I prefer not to use CUMIPMT for several reasons, chiefly: it calculates the periodic payment internally, which might not be realistic.

Instead, I prefer to use the payment calculated in D9, namely:

=PMT(RATE(12, 0, -1, 1+7.2%), D8*12, -D6)

That allows for real-world changes. For example, the payment must be rounded (typcially rounded up) at least to the cent. But it is common to round (up) to a multiple of $0.50 or to the dollar.