A floating-rate loan resets its interest rate using a benchmark, margin, and contractual conventions such as floors, caps, reset dates, and fallback rules.
A floating-rate loan, also called a variable-rate loan, is a loan whose interest rate can change under a contractual formula instead of remaining fixed for the full term. The rate commonly equals a benchmark plus a borrower margin, subject to reset dates, floors, caps, day-count rules, and benchmark fallbacks.
The lender cannot ordinarily change the rate arbitrarily. The agreement determines which inputs can change, when they are observed, and how the resulting interest is calculated.
A common formula is:
The contract may also apply:
The margin is not the same as the benchmark. It generally reflects borrower credit, collateral, maturity, capital, liquidity, product costs, and lender economics.
Suppose a $5 million commercial loan uses three-month Term SOFR plus a 2.25% margin. The benchmark fixing is 4.90%, the accrual period is 92 days, and the contract uses Actual/360.
The annualized all-in rate is:
Illustrative period interest is:
At the next reset, the contract uses the new benchmark fixing while the 2.25% margin remains unchanged unless a pricing grid or amendment changes it.
Assume the same margin is 2.25%, the observed benchmark falls to 0.50%, and the agreement has a 1.00% benchmark floor.
Without the floor, the formula would produce 2.75%. The floor therefore benefits the lender and limits how much the borrower’s rate falls.
Read whether the floor applies to the benchmark before the margin or to the all-in rate after the margin. Those structures are not equivalent.
| Convention | How the period rate is determined | Main timing issue |
|---|---|---|
| Forward-looking term rate | One published tenor fixing near period start | Rate is usually known in advance |
| Daily simple rate | Daily observations are averaged without compounding | Requires daily data and holiday rules |
| Compounded in arrears | Daily overnight observations compound over the period | Final amount is known near period end |
| Base or prime rate | Bank-published or contract-defined base changes when announced | Can reset immediately or on specified dates |
| Indexed consumer rate | Published index plus margin, subject to adjustment limits | Disclosure and payment-reset rules matter |
Alternative reference rates such as SOFR and SONIA introduced new compounding, lookback, and payment-notice conventions after LIBOR’s cessation.
| Feature | Floating-rate loan | Fixed-rate loan |
|---|---|---|
| Interest rate | Resets under a formula | Stays fixed for the stated fixed period |
| Borrower exposure | Cost rises when the benchmark rises | Market-rate increases do not change the contractual fixed rate |
| Benefit when rates fall | Rate may decline, subject to floors | Borrower keeps paying the fixed rate unless refinancing |
| Lender exposure | Yield adjusts with the benchmark | Lender bears more opportunity cost if market rates rise |
| Forecasting | Future interest is uncertain | Scheduled interest is more predictable |
| Prepayment economics | May have breakage or repricing provisions | May have prepayment premiums or yield maintenance |
Neither structure is universally better. The relevant comparison depends on term, cash-flow capacity, hedging, fees, floors, prepayment rights, and the borrower’s tolerance for changing payments.
“Floating-rate loan” is the broad concept. An adjustable-rate mortgage is a mortgage-specific form with consumer disclosures and adjustment features that can include:
A corporate revolver may instead use daily SOFR, a leverage-based margin grid, commitment fees, and borrower elections among rate options. The generic variable-rate label does not capture those product differences.
Borrowers may choose or accept floating pricing because:
These are structural reasons, not predictions that rates will fall.
A borrower can overlay floating debt with:
The hedge may not match perfectly. Differences in benchmark, tenor, reset date, compounding, floor, notional, amortization, or fallback can create basis risk.
Review:
This article provides general financial education, not personalized borrowing, investment, accounting, tax, or legal advice. Use the governing agreement and qualified professional review for a specific loan.