The headline interest rate is only one component of the true cost of debt. Here is how to calculate the total cost of capital, what drives the risk margin, and how the facility term and repayment profile make all the difference.
When evaluating debt, founders often focus solely on the nominal interest rate. Yet the true commercial price of borrowing is dictated by the interest rate, term length, repayment structure, and associated fees combined. Understanding these four parameters is the only way to compare finance proposals accurately.
How is a commercial interest rate structured?
Commercial interest rates typically consist of a base rate (pegged to reference benchmarks such as Euribor or swap rates) plus a lender risk margin. This risk premium reflects the credit profile of your business: the stronger your underlying cash flow, balance sheet solvency, and asset security, the narrower the risk margin.
- The risk profile of the business and broader industry sector
- Collateral and security: unencumbered asset cover generally secures lower pricing
- Maturity profile and fixed-rate periods
- Lender type: clearing bank, credit union, private debt fund, or fintech platform
Ancillary borrowing costs
- Arrangement, underwriting, or facility fees
- Professional valuation fees and legal/notary charges for registering security
- Commitment fees levied on undrawn credit lines
- Guarantee scheme costs, such as the state-backed BMKB scheme premium
- Prepayment penalties or break costs for early settlement
Worked examples
Example 1: €50,000 borrowing over 5 years at 8% on a straight-line amortisation basis. Capital is paid down at €10,000 annually; cumulative interest costs equal roughly €12,000.
Example 2: €250,000 borrowing over 10 years at 6% structured as an annuity loan. Monthly payments run at approximately €2,775, generating a total interest cost of around €83,000.
These worked models are illustrative and exclude ancillary facility fees. Use our finance calculator to evaluate your tailored funding requirements across interest rates, maturities, and repayment schedules, complete with real-time DSCR calculations.
Straight-line amortisation or annuity?
Under straight-line amortisation, you repay a fixed capital instalment each period plus declining interest: early cash outflows are highest, but total interest paid across the term is reduced. With an annuity structure, the aggregate monthly repayment remains flat — ensuring predictability for working capital budgeting — but results in a higher cumulative interest bill.
Practical ways to reduce borrowing costs
- Submit an exhaustive, well-substantiated credit submission pack
- Calibrate the borrowing term to the asset life, avoiding unnecessarily long facilities
- Tender across multiple lenders to compare total borrowing costs rather than headline margin
- Offer robust security or blend term debt alongside leasing or factoring
Frequently asked questions
- What represents a standard interest rate for a commercial loan?
- Rates vary markedly depending on credit risk, underlying security, and lender type. Senior bank loans backed by fixed property or plant sit materially below uncollateralised online facilities. Always tender for several termsheets and benchmark total cost of borrowing.
- Is commercial loan interest tax-deductible?
- Interest incurred on commercial borrowing is typically deductible as an allowable business expense, subject to corporate tax interest deductibility limitations. Consult your accountant or tax advisor regarding your precise corporate setup.
- How do I calculate the monthly repayment on a commercial facility?
- Use our finance calculator: enter your principal amount, interest rate, term, and repayment frequency to immediately view monthly debt service, cumulative interest expense, and the resulting DSCR.