weighted average life vs average life
Weighted-average life[edit] Main article: Weighted-average life. The number weighted average of the times of the principal repayments of an amortizing loan is referred to as the weighted-average life (WAL), also called average life. It's the average time until a dollar of principal is repaid.
The average life is the length of time the principal of a debt issue is expected to be outstanding. The average life is an average period before a debt is repaid through amortization or sinking fund payments.