Allow me to indulge in a little rant about INTEREST COVERAGE...
We have ... [Net Earnings before Interest] / [Periodic Interest Payments]
Note for the time being that:
(1) Numerator is a composite accrual of sorts (revenue vs. expenses)
(2) Denominator is the current portion of a perennial liability (interest component = CL; principal = NCL)
Interest Cover is not a "random" formula per se. The rationale can be derived intuitively in the sense that interest expense is just another addendum to the business' operating expenditures and therefore would take another chunk out of the bottom line.
We use this ratio on the basis that financing charges should ideally be considered separately from operational expenses.
To exemplify, a hardware store is in the business of sourcing hardware inventory from distributors/wholesalers and then offering to supply retail customers as a service. That's the revenue generating business model. Buy HW ---> Sell HW.
The store may require debt financing at certain stages throughout it being a going concern but fundamentally it's not in the business of borrowing funds. Debt is one of the means to an end but not the end in itself.
Now, said HW store will sell its wares at x% markup, take out COGS to arrive at gross then make other miscellaneous revenue (discount) adjustments.
Typical expenses from ordinary course of operations: salaries, office supplies, depreciation, utility bills, insurance, delivery/courier...
Take aggregate expenses away from the adjusted gross and we get our subtotal EBIT.
Creditors have precedence in terms of claims over this raw profit figure; equity holders have residual claim only. The business will look at its raw EBIT and determine how many times it can use that sum to pay off its loan interest liabilities AS AND WHEN THEY FALL DUE. Interest cover is a measure of redundancy and determines how probable it would be for the business to remain solvent. The more times the cover, the greater the certainty of future going concern.
Potential Issues:
1. Negative EBIT, ie. loss/deficit. The ratio becomes negative meaningless. A negative Int Cvr ratio suggests how many times the lender would need to pay you (the borrower) the interest payments which you owe them in order for you to nullify that loss.
2. The nature of accruals being that they're earned but not necessarily realized. If the Int Cvr ratio was [cash at bank] / [interest payments] then they'd be no issue.
However, if the business' trade debtors decide to delay payment of their invoices to the extent that cash inflows become an operating CONSTRAINT then that would have reverberating ramifications on your ability to pay your creditors; in particular, those of the institutional lending kind.
The business will still register the revenue as earned on their books but the Int Cvr ratio is no longer INFORMATIVE in the sense that said revenue and profit have not been realized in order to meet interest (as well as other) obligations of the liability kind as and when they fall due.
...I'm done.