Debt service review

Measure the mortgage load before it measures you.

AssetRoof converts rent, leverage, rate and reserve inputs into a monthly payment view, debt service coverage ratio, and post-finance cash flow. The point is not optimism. The point is durability.

Calculate mortgage cash flow Back to yield tool

Median LTV reviewed this week: 71% Typical reserve used: 5.8% of rent DSCR threshold watched most: 1.25x

Reference snapshot

For a £310,000 unit with 30% equity and a 5.3% rate, the debt payment can remain manageable only if rent collection holds.

Loan amount£217,000

Monthly debt service£1,312

DSCR1.33x

Monthly cash flow£442

Mortgage and cash flow calculator

Set the debt shape, then compare annual income to debt service and reserve drag.

Amortising loan model with monthly repayment.

Results

Loan amount—

Monthly mortgage payment—

Debt service coverage ratio—

Monthly cash flow after debt—

A DSCR below 1.20x usually deserves another look, especially when rents are still stabilising.

How to read the output

A mortgage model becomes useful when it stays tied to operating reality.

Start with leverage

Small changes in deposit size can shift both payment burden and refinance flexibility.

Keep reserves visible

Reserve drag is not decorative. It is what absorbs boiler failures, voids and compliance work.

Watch DSCR as a habit

The ratio is simple, but it catches weak coverage early and keeps underwriting language disciplined.

Frequently asked questions

Common points that come up when investors move from listing review to financing decisions.

Does the tool use a fixed rate

Yes. It models a standard fixed annual rate entered by the user and converts it to monthly repayment.

Can I model interest-only debt

Not on this page. Use the amortising loan output as a stricter baseline and compare it with lender terms separately.

Why include reserves outside monthly costs

It keeps operating drag visible even when a landlord has been lucky for several months in a row.

What does DSCR mean here

Debt service coverage ratio equals monthly operating income divided by monthly mortgage payment.