About

Mispricing a bond's coupon rate by even 0.1% on a $1,000,000 portfolio compounds to thousands in misallocated cash flow annually. The coupon rate C_r is the fixed annual interest a bond issuer pays relative to the bond's F (face value), not its market price. Confusing coupon rate with current yield Y_c is the most common error in fixed-income analysis. This calculator computes the nominal coupon rate, the current yield based on market price, and the per-period coupon payment for any payment frequency. It assumes a standard fixed-rate bond with no embedded options. Results do not account for tax treatment, day-count conventions beyond simple division, or credit spread adjustments.

Formulas

The coupon rate expresses the annual coupon payment as a percentage of the bond's face (par) value:

C_r = CF × 100

The current yield measures income return relative to the bond's current market price:

Y_c = CP_m × 100

The coupon payment per period divides the annual coupon by the number of payment periods per year:

C_p = Cn

The dirty price of a bond is the clean (market) price plus accrued interest:

P_dirty = P_m + AI

Where: C_r = coupon rate (%), C = annual coupon payment ($), F = face (par) value ($), P_m = current market price ($), Y_c = current yield (%), C_p = coupon per period ($), n = payment frequency (periods per year), AI = accrued interest ($), P_dirty = dirty price ($).

Reference Data

Bond Type	Typical Coupon Range	Payment Frequency	Day-Count Convention	Risk Level
U.S. Treasury Bond	2 - 5%	Semi-Annual	Actual/Actual	Risk-Free Benchmark
U.S. Treasury Note	1.5 - 4.5%	Semi-Annual	Actual/Actual	Risk-Free Benchmark
Investment-Grade Corporate	3 - 6%	Semi-Annual	30/360	Low - Medium
High-Yield Corporate	6 - 12%	Semi-Annual	30/360	High
Municipal Bond	2 - 5%	Semi-Annual	30/360	Low
Zero-Coupon Bond	0%	None (Discount)	Actual/Actual	Varies
Eurobond	1 - 7%	Annual	Actual/Actual	Varies
UK Gilt	0.5 - 4%	Semi-Annual	Actual/365	Low
Japanese Government Bond	0.05 - 1.5%	Semi-Annual	Actual/365	Low
Emerging Market Sovereign	5 - 15%	Semi-Annual / Annual	30/360	High
Convertible Bond	1 - 4%	Semi-Annual	30/360	Medium
Floating Rate Note (FRN)	SOFR + 50 - 300 bps	Quarterly	Actual/360	Low - Medium
Inflation-Linked (TIPS)	0.1 - 2% (real)	Semi-Annual	Actual/Actual	Low
Perpetual Bond	4 - 8%	Semi-Annual / Annual	Varies	Medium - High
Agency Bond (GSE)	2 - 5%	Semi-Annual	30/360	Low
Sukuk (Islamic Bond)	3 - 7%	Semi-Annual	Actual/Actual	Varies

Frequently Asked Questions

Coupon rate is fixed at issuance and calculated against the bond's face value F. Current yield Y_c divides the same annual coupon C by the bond's current market price P_m. When a bond trades at par, both values are equal. When a bond trades at a discount (P_m < F), current yield exceeds the coupon rate. The reverse holds for bonds trading at a premium.

Payment frequency n determines the size and timing of each cash flow. A bond with a 6% annual coupon on a $1,000 face value pays $60 once annually, but $30 twice if semi-annual. More frequent payments slightly increase the effective annual return due to reinvestment opportunity, which is captured by yield-to-maturity (YTM) rather than the nominal coupon rate.

Between coupon dates, the seller has earned a portion of the next coupon payment. The buyer compensates the seller for this via accrued interest AI. The dirty price (P_dirty = P_m + AI) is what the buyer actually pays. Market quotes typically show the clean price P_m. Failing to account for accrued interest leads to underestimating true acquisition cost.

Yes. Zero-coupon bonds pay no periodic interest. They are issued at a deep discount to face value and redeemed at par at maturity. The return comes entirely from price appreciation. Entering 0 as the annual coupon in this calculator correctly returns a coupon rate of 0%. Current yield is also 0% since there is no income stream.

No. This tool uses simple division (C ÷ n) for per-period payments. Real-world bond markets use day-count conventions such as 30/360, Actual/365, or Actual/Actual to prorate accrued interest precisely. For exact settlement calculations, you need to apply the specific convention mandated by the bond's prospectus. The accrued interest field here accepts a user-supplied value for flexibility.

When P_m > F, the current yield drops below the coupon rate. This reflects that the buyer pays more than par for the same fixed coupon stream, reducing the effective income percentage. The coupon rate itself remains unchanged. A bond trading at $1,100 with a 5% coupon on $1,000 par has a current yield of approximately 4.55%.