Estimate your commercial mortgage repayments in seconds.
Enter the loan amount, rate, and term to see monthly repayments and total interest. Use this as a quick guide before speaking to a lender or broker.
When you are looking at buying or refinancing a commercial property, the first thing most people want to know is simple: what will it cost me each month?
This calculator gives you a straight answer. Enter the amount you need, the term of the loan, and an interest rate that feels realistic. You will get an estimate of what your monthly commercial mortgage repayments might look like, along with the total amount you would pay over time.
It is not about selling you anything – it is about giving you a clear view before you sit down with a lender or make a big commitment.
And if you do want to talk through your options, as a whole-of-market commercial mortgage broker, we can help you work out what is achievable and what is best left on paper for now.
What Is a Commercial Mortgage?
A commercial mortgage is a straightforward concept. It is a loan that helps a business buy or refinance property – the kind of place where the work actually happens. Offices, warehouses, shops, units.
It is similar to a normal mortgage, just built for business property – so in essence, just a business mortgage. You can use it to buy somewhere new, refinance an existing site, or raise money from a building you already own.
Most run for several years, often between three and twenty-five, and are repaid monthly. The details – how much you can borrow, the rate, the terms – all depend on the property and the strength of the business behind it.
For many owners, it is not just a loan. It is a way to take control – to own the space instead of renting it, and to build something solid for the long term.
How Does a Commercial Mortgage Calculator UK Work?
A commercial mortgage calculator is there to give you a rough idea of what borrowing might look like – nothing fancy, just the basics. You type in a few details, and it does the sums.
Start with the property value, then add the amount you want to borrow, how long you would like the loan for, and the interest rate you think applies.
From that, the calculator gives you an estimate of what your monthly repayments could be and roughly how much you would pay in total over the term.
It is not a promise or a mortgage offer of course – it is just a way to see if the numbers make sense before you start talking to lenders. A quick reality check, so you know what you are walking into before you maybe start speaking with a commercial mortgage broker.
Why Use a Commercial Mortgage Payment Calculator?
Because before you borrow, you need to know what you are dealing with.
A commercial mortgage is a big step and the numbers can look very different once you spread them over years. A commercial mortgage estimator helps you see that clearly. You can play with the figures, change the loan amount, adjust the term, try different interest rates – and see what happens to the repayments.
It is a quick way to get your head around what is realistic for your business. No sales talk, no guesswork – just a rough picture of what the loan could look like in real life.
It is better to find that out now, on your screen, than later when you are sitting in front of a lender.
Key Things to Know Before Using a Commercial Mortgage Estimator
Before you start punching numbers in, remember this: a calculator can only give you a rough idea. It is useful, but it is not the full story.
Every deal depends on the details – the property, the business, and the person behind it. Commercial mortgage lenders do not just look at figures – they look at risk, stability, and whether the deal actually makes sense.
A few things matter more than people expect: how much deposit you have got, what kind of property it is, how long you have been trading, and what shape your accounts are in. Even the location can make a difference.
So yes, use the business mortgage calculator – see what the repayments might look like. But do not mistake it for an answer. It is just a way to get a feel for the numbers before you sit down with someone who can look at the whole picture.
Estimate Commercial Mortgage Costs in Seconds
Use the calculator below to estimate monthly commercial mortgage interest and total borrowing costs based on typical business mortgage rates.
Feel free to use our Finance Calculator
**Note: For exceeding 120 no. of payments, a group of 12 payments will be combined into a single payment number for better chart visibility.
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Figures are indicative only, based on typical UK commercial mortgage assumptions.
This focuses on repayments and borrowing costs – not fees, valuation costs, legal work, or the wider deal structure.
What this calculator shows
Estimated monthly repayments and total interest based on the figures you enter.
What this does not include
Fees, valuation costs, legal work, or how the deal is structured – all of which can affect the final terms.
Want a more accurate figure based on your deal? We can sense-check it quickly.
Example: What This Might Look Like in Practice
Say you are buying a commercial property for £500,000.
You put down a 30% deposit (£150,000), so you are borrowing £350,000.
The rate comes in at around 6.75% over 20 years.
That would put repayments somewhere in the region of £2,600 – £2,800 per month.
But this is where it usually shifts.
Different lenders will stress the deal differently, price risk differently, and structure it in their own way – so the final numbers can move once it is properly assessed.
This is why two lenders can give you completely different terms on the same deal.
Most commercial mortgages land somewhere around 65% to 75% loan-to-value, although that can move depending on the property and the strength of the deal.
Rates typically start from around 6%+, but pricing can shift quite a bit once a lender actually looks at the full picture.
Stress Testing: How Lenders Pressure-Test the Numbers
The figure a calculator gives you is a starting point. Before a lender agrees to anything, they run the deal through their own affordability test, and that test is deliberately harder than the pay rate suggests. This is stress testing, and it is where a lot of applications either firm up or fall down.
The method depends on what the property is for.
For an investment property that will be let to tenants, the lender tests whether the rent covers the interest. This is the interest cover ratio, usually shortened to ICR, and it compares annual rental income against annual interest at the rate being tested. A figure of 100% means the rent only just meets the interest, which no lender accepts. Most commercial lenders want somewhere between 125% and 145%, so the rent has to clear the interest by a real margin. At 130%, the property brings in £130 of rent for every £100 of interest.
Where the borrower’s own business trades from the building, the test changes name and shape. This is the debt service coverage ratio, or DSCR, and it measures business earnings against the full annual debt service, capital as well as interest. It is quoted as a multiple rather than a percentage, and 1.25x is the common minimum.
On top of that, many lenders calculate the cover at a rate above the one you would actually pay. They might quote you 7% but test the deal at 8% or 9% to check it still holds if rates climb. A deal that works at the pay rate can still be declined if it fails at the stressed rate.
For an owner-occupied property, where your own business trades from the building, the lender assesses the business rather than a rental figure. They look at your accounts, work out how much profit the business generates, and check whether that profit services the mortgage once the payment replaces whatever rent you were paying before. Strong, stable trading figures make this straightforward. Thin margins or a recent dip in profit make it harder, and the lender may want to understand why.
Here is what stress testing looks like in practice on an investment deal. Say you are borrowing £350,000 at 7% over 20 years, with monthly repayments of around £2,700, which is £32,400 a year. If the property lets for £46,000 a year, your cover sits at roughly 142%, which most lenders would be comfortable with. Now apply a stress rate of 9%. The annual cost rises to around £37,800, and the cover drops to about 122%. At that point some lenders would pull back or ask for a larger deposit, even though nothing about the rent has changed.
This is the reason two lenders can look at the same property and reach different conclusions. They are not testing the same numbers.
Rental vs Owner-Occupied: Two Different Deals
A calculator treats every loan the same way, but a lender does not. The single biggest factor in how your application is assessed is whether you plan to trade from the property yourself or let it out to someone else. These are handled as two separate types of deal, with different rates, different loan-to-value limits, and different questions to answer.
An owner-occupied commercial mortgage is for a business buying the premises it will operate from. A dental practice buying its surgery, a manufacturer buying its unit, a shop buying its own retail space. Because the building supports a trading business, the lender leans on that business to judge affordability. Owner-occupied deals often attract slightly higher loan-to-value, in some cases up to 75% or 80%, because the lender sees an owner with a direct stake in keeping the business and the property going.
An investment commercial mortgage is for a property you intend to let to a tenant and hold for the rental income. Here the tenant pays the rent, the rent services the loan, and the lender assesses the deal on that rental income through the DSCR method covered above. Loan-to-value on investment deals usually lands between 65% and 75%, reflecting the fact that the income depends on a tenant staying in place and paying.
A worked comparison shows how far the two can diverge on a property of the same value.
Take a £400,000 property. As an owner-occupied purchase, a trading business with solid accounts might secure 75% lending, so £300,000, assessed against the profit the business produces. As an investment purchase, the same £400,000 building might be capped at 70%, so £280,000, and the lender would want the rental income to clear the mortgage by at least 125% before agreeing. Same building, two different loans, two different deposits, and two different sets of questions at the underwriting stage.
Knowing which category your deal falls into before you approach a lender saves a great deal of wasted effort, because it tells you which lenders to approach and what they will ask for.
More Worked Examples
The £500,000 case above sits in the middle of the range. Two more scenarios, one smaller and one larger, show how the figures behave at each end.
Start small, with an owner-occupier. A café owner buys the freehold of the unit they have rented for years. The price is £250,000. A 25% deposit puts £62,500 down and leaves £187,500 to borrow. At 7% over 15 years, repayments come to around £1,685 a month. The business already trades from these premises, so the lender judges affordability on the café accounts. In practice the mortgage payment steps into the place the rent used to occupy, money that was leaving the business each month regardless.
Now go larger, with an investor. A buyer takes on a small parade of retail units priced at £900,000. Lending is capped at 70%, giving a loan of £630,000 against £270,000 of the buyer’s own funds. At 7.25% over 25 years, repayments reach roughly £4,550 a month, or £54,600 a year. The units generate £78,000 in annual rent, which produces a DSCR near 143% and sits comfortably inside most lender thresholds. Apply a 9% stress rate and the annual cost climbs to about £63,500. Cover falls to around 123%, close to the level where a cautious lender begins asking harder questions.
One thread runs through all three examples. The calculator hands you a monthly figure. The deposit, the loan-to-value ceiling, and the affordability test all move according to the property and the party behind the deal.
Want to Sanity-Check Your Numbers?
If the figures look close, it is worth checking how a lender would actually see the deal.
A quick review can often highlight better options – or flag issues early before you commit time or costs.
Frequently Asked Questions (FAQs)
Will the calculator tell me exactly what I will pay?
Not exactly, but it will give you a ballpark figure – something to work from.
The real rate depends on your business, the property, and the deal you end up with. But it is a good place to start. In order to get an exact quote for your commercial mortgage, we recommend you speak with a commercial mortgage broker.
How much deposit do I actually need?
Most commercial mortgage lenders want you to put in at least 25% of the property’s value for commercial mortgages.
More deposit is better however – as it shows your commitment to the lender and usually secures you a better rate, since less risk.
What if my business is new?
It is tougher, but certainly still possible to secure a commercial mortgage. Some lenders will look at projections or other assets you might own.
The commercial mortgage calculator still helps you estimate what kind of payments you would be taking on if things line up.
Can I use the calculator for a property I am buying to rent out?
Yes, absolutely – the maths is the same. Just remember that commercial mortgage lenders treat investment and owner-occupied deals differently, so rates will vary.
We recommend you speak with a specialist commercial finance broker for best advice and options.
Can the calculator tell me if I will actually get approved?
No, it cannot do that – it is not that clever! It just runs the numbers. Approval depends on the lender, your business, your credit, and how solid the deal looks on paper.
The calculator helps you see if it is worth the conversation in the first place. In order to determine if you can get approved for your mortgage, speak with a commercial mortgage broker.
Should I speak to a broker before applying for a commercial mortgage?
Short answer – you will probably save yourself a headache if you do. Commercial finance lenders do not all play by the same rules.
One might like your deal, another will not touch it – and that can change week to week. Go in blind and you can easily end up down the wrong path. Most people only realise that after they have already lost time.
A quick chat upfront just helps you avoid that.
Can I get a more accurate commercial mortgage quote?
Not from a calculator, no. It will point you in roughly the right direction, but that is about it.
The real numbers only start to show once someone digs into the deal properly – and that is where things tend to move. Sometimes it improves. Sometimes it does not.
Either way, it stops being guesswork.
Summary
A commercial mortgage calculator UK is there to give you a feel for the numbers before you take things further. It helps you see what the payments might look like, how long the loan could run for, and what it all adds up to in the end. Nothing fancy – just a clear picture to work from to help calculate your business mortgage costs.
Every business and every property is different. The calculator will not tell you exactly what a lender will offer, but it will help you understand what is realistic and what is not. That is often all you need at the start – a bit of clarity before you make big decisions.
If you are thinking about buying or refinancing a property, run a few numbers. Then talk it through with someone who knows how these deals actually work. A good commercial mortgage broker can turn a rough idea into a plan that fits your business, your goals, and your pace.
Commercial Finance Network is a whole-of-market FCA authorised broker working with property investors, developers, and businesses across the UK and internationally. We work across the full specialist commercial mortgage panel and will tell you which lenders will engage with your deal, what LTV and rate to expect, and how to structure the application before anything is submitted. We are directly authorised and regulated by the Financial Conduct Authority. Your property may be repossessed if you do not keep up repayments on a loan secured against it.
Call: +44 1494 622 111
Email: info@cfnuk.com
Related Pages
- Commercial Mortgage Rates UK – current rate ranges by LTV band, property type and borrower profile
- Bridging Loan Calculator – estimate monthly costs and total interest on short-term bridging finance
- Buy-to-Let Mortgage Calculator – estimate repayments on BTL mortgage borrowing for investment properties
- Bridging Loans – short-term finance often used to fund commercial property purchases before a term mortgage is in place
- Ltd Company Commercial Mortgage UK – how lenders assess limited company applications, LTV expectations, personal guarantees and what to prepare