📊 Interest Rate Cap Calculator
Calculate the cost and benefits of interest rate cap protection for commercial loans
Loan & Cap Details
Rate above which cap provides protection
Margin above reference rate
Higher volatility = higher cap premium
ILLUSTRATIVE CAP PREMIUM
$18,902.29
Flat-rate model estimate, not a live market quote.
0.378% of loan amount
38 basis points
$3,780/year amortized
Key Metrics
vs. Fixed Rate Alternative
Total 5-year cost: $1.25M
Total 5-year cost: $1.64M
Rate Rise Scenarios
| Scenario | Reference Rate | All-In Rate | Capped Rate | Annual Interest | Cap Payment | Net Cost |
|---|---|---|---|---|---|---|
| Current (No Rise) | 3.50% | 6.00% | 6.00% | $300K | — | $300K |
| Moderate Rise (+1%) | 4.50% | 7.00% | 7.00% | $350K | — | $350K |
| Significant Rise (+2%) | 5.50% | 8.00% | 7.50% | $400K | $25K | $375K |
| Major Rise (+3%) | 6.50% | 9.00% | 7.50% | $450K | $75K | $375K |
Cap provides protection when reference rate exceeds 5.00%. All figures are annual.
How Interest Rate Caps Work
Protection
An interest rate cap protects floating-rate borrowers from rate increases above the strike rate. You pay an upfront premium for this insurance.
Payments
When SOFR exceeds the cap strike, the cap issuer compensates you for the difference, effectively capping your interest rate.
Pricing Factors
Cap premium depends on: strike rate vs. current rate, loan term, rate volatility, and market expectations. Higher volatility = higher premium.
How this estimate works
Black-76 caplet values are summed over quarterly periods. This illustration holds your reference rate and volatility constant, uses 0.25-year accruals, and discounts each payment at the same quarterly-compounded reference rate. The first quarter fixes today. Loan spread affects the loan-payment scenarios, not the cap premium.
Inputs are assumptions, not live SOFR, market forward rates, or dealer quotes. Actual contracts require their fixing dates, day-count rules, discount curve and volatility surface; compounded overnight SOFR caps may require a different model. The cost comparisons on this page are illustrative scenarios, not forecasts.
Reference: QuantLib Black cap/floor pricing implementation⚠️ Important Disclaimer:This calculator provides estimates based on simplified pricing models. Actual cap premiums vary by lender, market conditions, counterparty credit risk, and specific loan terms. Consult with a derivatives specialist or treasury advisor for precise quotes. Interest rate caps are complex financial instruments; ensure you understand the terms before purchasing.
About This Calculator
Explore an illustrative interest rate cap premium using a flat reference rate, constant volatility, quarterly accruals and discounted Black-76 caplet values. Compare loan-payment scenarios using your own assumptions. This calculator does not use live market data or provide a dealer quote.
Frequently Asked Questions
How much does an interest rate cap cost and what affects the premium?
There is no single market price. In this model, premium depends on the loan amount, term, strike, assumed reference rate and volatility. With the default inputs ($5 million, 5 years, 5% strike, 3.5% reference rate and 20% volatility), the illustrative premium is about $18,902. Actual quotes require market curves, contract details and dealer pricing.
How should I compare a cap with a fixed-rate loan?
Compare actual loan offers over the same term and principal. Include the floating reference rate, loan spread, upfront cap premium, fees and prepayment terms. A cap limits the covered reference-rate exposure; the loan spread still applies. The scenarios on this page are assumptions, not forecasts or a recommendation to choose either loan.
How do I use this calculator?
Adjust the sliders for loan amount, term, cap strike, assumed reference rate, loan spread and volatility. The estimate updates automatically. Loan spread changes the payment comparisons but not the cap premium. Use the same assumptions when comparing scenarios.
Does this calculator use live rates or provide an accurate market quote?
No. It assumes a flat reference-rate curve and constant volatility, with quarterly accruals and discounting. The first quarter fixes today. Actual fixing dates, day-count rules, market curves and volatility surfaces can materially change the price. Compounded overnight SOFR contracts may need a different model. Use a qualified provider for a contract-specific quote.
Can I save or share my result?
You can take a screenshot and record your input values. Sharing the page URL does not save those values; the recipient must enter the same assumptions to reproduce your estimate.
The SuperCalc Editorial Team maintains calculator interfaces, formula notes, examples, and supporting explanations. Methods, assumptions, source links, and review depth vary by calculator and are documented on the relevant page where available.