Calculate repayments on multiple interest free loans

Question

Say I have an undetermined number of loans or varying amounts.

Each loan has it's own interest-free period which expires on a different date.

I want to calculate a single payment, (Either weekly, fortnightly or monthly) that does not change, to pay back all the loans before the respective interest-free periods expire.

---

Sample Data:

+-------------+------------------------------+
| Loan Amount | Interest Free Period Expires |
+-------------+------------------------------+
| $524.50     | 05 June 2018                 |
+-------------+------------------------------+
| $450.02     | 11 July 2018                 |
+-------------+------------------------------+

---

This data could change at any time i.e. another loan added.

So I am looking for a formula that is scalable.

Answer 1

Add up the balances, divide by the number of periods until the first expiration date. On that date you'll be all paid up. If new loans come in along the way, you have to recalculate.

If you want to keep some of the interest free money longer and want a fixed payment, I don't think that can always be done. If you had two loans and one was due tomorrow; the other a year from now there's no way to space out payments uniformly.