Interest only loan

This will calculate: the interest owed on a loan where nothing is paid until the due date. Interest accrues on a 365 day year with no periodic payments.

You get two figures. Total interest due compounds at whatever interval you pick, so unpaid interest starts earning interest itself. Simple interest does not compound at all — it is just rate × days.

The gap between them is what the compounding is costing. Enter dates as 1/1/26 or 01/01/26.