Commercial mortgage calculator
This commercial mortgage calculator will estimate monthly repayments and rent cover on business property from your own figures. The calculator is coming soon; the guide below explains each input.
Reviewed by David Sampson, Founder & Director · Created 20 October 2026 · Last reviewed 20 October 2026
What will the commercial mortgage calculator show?
A commercial mortgage calculator estimates the monthly repayment and total interest on a loan secured on business property, such as an office, shop or industrial unit. Enter the property price, deposit, interest rate and term. For a let property, add the annual rent to see how far it covers the interest, which is how lenders start their test.
Every figure will be an input, so the result reflects the numbers entered rather than market data. It is a planning estimate, not a quote or a lending decision. How commercial mortgages work, for owner-occupiers and investors, is explained in the commercial mortgages section.
The inputs explained
The loan is the price less the deposit, and the loan-to-value is the loan divided by the property's value. The rate should come from a quote or illustration, and the term is the number of years agreed with the lender. Repayment loans reduce the balance, while interest-only loans keep it the same over the term.
The term affects both the monthly payment and the total cost. A longer term lowers the payment but increases the interest paid overall, while a shorter term does the opposite. Commercial terms are often shorter than home loan terms, so testing a few lengths shows the trade-off before a lender is approached.
For investment property, the rent is the annual rent under the lease. Lenders use their own valuation and their own view of the rent, so their figures may differ from those entered. How lenders price commercial loans is set out on the commercial mortgage rates page.
Using the result
The result helps set a budget and compare options before speaking to a lender or broker. Testing a higher rate, a lower rent or a period without a tenant shows how sensitive the loan is to change. Arrangement, valuation and legal fees, and Stamp Duty Land Tax, are not included and need adding separately.
Until the calculator is live, the same sums can be worked out by hand. Interest-only cost is the loan multiplied by the annual rate, divided by twelve for the monthly figure. A broker can quote current pricing for a specific case.
Frequently asked questions
How do I calculate a commercial mortgage repayment?
For interest-only, multiply the loan by the annual rate and divide by twelve. A repayment loan costs more each month because part of each payment reduces the balance.
How do I calculate my loan to value?
Divide the loan by the property's value and multiply by one hundred. Lenders use their own valuation, not the price.
Is the commercial mortgage calculator live?
Not yet. The calculator is coming soon. The guide on this page explains each input so the figures can be prepared.
Does the calculator give a quote?
No. It will use the figures entered. A lender's offer depends on its valuation, the business or tenant and its own criteria.
How long is a typical commercial mortgage?
Terms vary by lender and case. Commercial mortgages are often shorter than home loans, and some lenders offer longer terms on strong cases.
Are fees included in the calculator?
No. Arrangement, valuation and legal fees and Stamp Duty Land Tax vary by case and need to be added separately.
Important: Your home may be repossessed if you do not keep up repayments on your mortgage. Information on this page is for general guidance only and does not constitute financial advice.Always verify details directly and seek independent advice before making financial decisions.