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Bond Yield Calculator

Computes a bond's current yield and solves numerically for its yield to maturity from face value, coupon rate, market price, years to maturity and coupon frequency, and reports total coupon income and total return if held to maturity.

When to use

You know a bond's price and coupon and want its yield to maturity (the annualized return if held to redemption) or want to compare bonds trading at different prices.

Do not use when: The bond is callable, floating-rate or amortizing (yield to call / worst differ), or you want the price from a yield (invert with present-value style discounting).

Formula

C = face_value × coupon_rate_percent/100 / m; N = years_to_maturity × m; solve price = Σ_{k=1..N} C/(1 + y)^k + face_value/(1 + y)^N for the periodic yield y; YTM = y × m; current_yield = annual coupon / price

Standard bond pricing with level coupons at the end of each period, settlement on a coupon date (no accrued interest) and the yield found by bisection. YTM assumes coupons are reinvested at the same yield.

Inputs

Parameter	Type	Unit	Required	Description
`face_value`	number		default 1000	Amount repaid at maturity. Range: > 0, ≤ 1000000000000
`coupon_rate_percent`	number	% per year	yes	Annual coupon as a percent of face value. Range: ≥ 0, ≤ 100
`price`	number		yes	Current clean price in currency (e.g. 950 for a 1,000 bond quoted at 95). Range: > 0, ≤ 1000000000000
`years_to_maturity`	number	years	yes	Time until redemption; rounded to whole coupon periods. Range: > 0, ≤ 100
`payments_per_year`	integer		default 2	2 for semiannual (US Treasuries and most corporates), 1 for annual (many European bonds). Range: ≥ 1, ≤ 12

Outputs

Output	Type	Unit	Description
`annual_coupon`	number		face_value × coupon_rate_percent / 100.
`coupon_payment`	number		annual_coupon / payments_per_year.
`number_of_payments`	integer		round(years_to_maturity × payments_per_year).
`current_yield_percent`	number	%	annual_coupon / price × 100.
`yield_to_maturity_percent`	number	%	Periodic yield × payments_per_year (bond-equivalent yield).
`effective_annual_yield_percent`	number	%	(1 + periodic yield)^payments_per_year − 1.
`total_coupon_income`	number		coupon_payment × number_of_payments.
`total_return_to_maturity`	number		total_coupon_income + face_value − price.
`price_status`	string		Discount (price below face), premium (above) or par.

Example

1,000 face, 5 % coupon, price 950, 10 years, semiannual: {"face_value":1000,"coupon_rate_percent":5,"price":950,"years_to_maturity":10,"payments_per_year":2} → {"annual_coupon":50,"coupon_payment":25,"number_of_payments":20,"current_yield_percent":5.26,"yield_to_maturity_percent":5.66,"effective_annual_yield_percent":5.74,"total_coupon_income":500,"total_return_to_maturity":550,"price_status":"Discount (price below face value)"}

1,000 face, 6 % annual coupon, price 1,050, 5 years: {"face_value":1000,"coupon_rate_percent":6,"price":1050,"years_to_maturity":5,"payments_per_year":1} → {"current_yield_percent":5.71,"yield_to_maturity_percent":4.85,"total_coupon_income":300,"total_return_to_maturity":250,"price_status":"Premium (price above face value)"}

GET https://tttkmbb.com/api/v1/calculate/bond-yield?face_value=1000&coupon_rate_percent=5&price=950&years_to_maturity=10&payments_per_year=2

Machine access

API: GET https://tttkmbb.com/api/v1/calculate/bond-yield (query parameters) or POST with a JSON body {"inputs": {...}}
Schema: https://tttkmbb.com/api/v1/calculators/bond-yield · Markdown: https://tttkmbb.com/finance/bond-yield.md · JSON definition: https://tttkmbb.com/finance/bond-yield.json
MCP: server https://tttkmbb.com/mcp, tool run_calculator with calculator_id="bond-yield"
OpenAPI operationId: calculate_bond_yield
Freshness: static. Authentication: none. Rate limit: fair use (see rate limits).

Sources

Investopedia – Yield to Maturity (YTM): What It Is and How It Works (reference)
Wikipedia – Yield to maturity (reference)
Investopedia – Current Yield (reference)

FAQ

Why is YTM above the current yield for a discount bond?

Current yield counts only coupons; YTM also includes the gain from being repaid 1,000 for a bond bought at 950, spread over the remaining years.

Is YTM the same as the bond-equivalent yield?

Yes for semiannual bonds: YTM here is the periodic yield times the number of periods per year (nominal), which is how US bond yields are quoted; effective_annual_yield_percent compounds it.

Related calculators

APY Calculator — Nominal versus effective annual rates.
Present Value Calculator — Discount a single future amount.
IRR Calculator — YTM is the IRR of the bond's cash flows.