Say the principal is 10,000. Annual rate is 5%. Tenor with 2 monthly period starting at Jan. The periodic payment in arrear is 1,300.

Interest for Jan is calculated as (10,000 * 5% * 31 / 360 = 43) The principal repaid is (1,300 - 43) = 1,257.

Interest for Feb is calculated as ((10,000-1,257) * 5% * 28 / 360 = 34) The principal repaid is (1,300 - 34) = 1,266.

The future value (aka balloon payment) would be 10,000 - 1,257 - 1,266 = 7,477.

So I would like to know if there is a calculation could be used to result

**7,477**by inputting the above data, rather than calculate the whole repayment schedule every each time.

I tried excel formula to see if it solved the situation, and the excel formula failed:

- FV function: future value of constant payments at constant interest rate
- FVschedule function: future value of no payments at variable compound interest