Debt service coverage ratio

Definition

The debt service coverage ratio (DSCR) is a measure of a business's ability to meet its debt repayments from its operating income. It is calculated as net operating income divided by total debt service — the cash the business produces, set against the loan principal and interest it must pay over the same period. A DSCR above 1.0 means income covers the repayments with room to spare.

In plain terms

DSCR answers a blunt question: for every pound of debt repayment due, how many pounds of income does the business actually generate? A DSCR of 1.0 means income exactly covers repayments with nothing left over — uncomfortably tight. A DSCR of 1.5 means you earn £1.50 for every £1 of debt service, a comfortable cushion.

Lenders lean on this ratio because it speaks directly to repayment, not just profitability. A business can be profitable yet have a weak DSCR if it is heavily borrowed, and it is repayment capacity — not headline profit — that decides whether a loan gets repaid on time.

How to calculate DSCR

The formula is straightforward:

DSCR = Net operating income ÷ Total debt service

Net operating income is broadly your earnings before interest and tax (close to EBITDA for many SMEs). Total debt service is all loan principal and interest payable over the period.

Item	Example
Net operating income (annual)	£150,000
Total debt service (annual)	£100,000
DSCR	1.5×

Here the business earns one and a half times what it needs to service its debt — a position most lenders view favourably.

Why it matters to your business

DSCR is one of the first things an underwriter calculates, and it often appears as a loan covenant — a condition you must keep meeting after drawdown. Fall below the agreed level and you can technically breach the agreement, even while still paying on time.

Knowing your own DSCR before you apply is powerful. It tells you how much additional borrowing your cash flow can realistically support, stops you over-committing, and lets you walk into a conversation with a lender already knowing roughly what they will conclude. If the ratio is tight, you can address it — lifting income or restructuring existing debt — before it becomes a decline.

An example

A manufacturer generates £200,000 in net operating income and currently services £120,000 of annual debt — a DSCR of 1.67×, comfortably healthy. It wants a new facility that would add £40,000 a year in repayments.

New total debt service becomes £160,000, dropping the DSCR to 1.25×. That still sits at the level many lenders require as a minimum, so the borrowing is affordable but leaves less margin for a downturn. The director can see, before applying, exactly how much headroom remains — and decide whether to borrow the full amount or hold something back.