The formula
How to calculate yield to maturity
Yield to maturity is the total annual return from holding a bond until it is redeemed: the coupons plus the difference between what you paid and what you get back. It is the number the bond market actually quotes.
The exact YTM has no closed-form solution — it has to be found by iteration. The approximation above spreads the redemption gain evenly across the remaining years and is accurate to within a few basis points for bonds trading near par.
The inputs, one by one:
- Face value
- Market price
- Coupon rate (%)
- Years to maturity (years)
Results appear immediately — there is nothing to submit. Changing a field rewrites the link, so you can share the exact scenario you are looking at.
The order the fields are filled in makes no difference to the result — the calculator recomputes the whole formula from whatever is currently in every field, not step by step. That means it is safe to adjust one number, watch the result change, and adjust it back, without worrying about resetting anything first.
Why yield to maturity matters
Most people who look up a yield to maturity calculation already have a specific number in mind — a quote, an offer, a target — and want to check it rather than learn the theory behind it. This page is built for that: enter your own figures, see the result immediately, and change any field to see how the answer moves without redoing the arithmetic from scratch each time.
This tends to come up when comparing two concrete alternatives — two lenders, two savings products, two ways of structuring the same decision — rather than in the abstract. Run both scenarios through the same calculator with the same assumptions and the comparison becomes fair, because the only thing changing between the two results is the number you are actually trying to test.
It is also worth being clear about what a single figure like this can and cannot settle on its own. It answers the specific question the formula was built to answer, and nothing more — a favourable yield to maturity result does not automatically mean a decision is a good one overall, since plenty of other factors that a formula cannot capture, from personal circumstances to how comfortable a commitment feels, usually matter just as much as the arithmetic. Use the number as one solid input among several rather than the whole of the decision.
A calculator like this one is often bookmarked and returned to repeatedly over months rather than used once, particularly for anything tied to an ongoing plan such as a mortgage, a savings goal or an investment being tracked. Because the figures live in the web address rather than only in memory, coming back to the same page with updated numbers is quicker than starting from a blank spreadsheet each time.
Worked example
Work through the defaults on this page:
- Face value: 1,000
- Market price: 920
- Coupon rate: 4.5 %
- Years to maturity: 6 years
That gives:
- Yield to maturity (approx.): 6.076 %
- Current yield: 4.891 %
- Gain at redemption: 80
These figures are only the calculator's own starting values, included so the working is visible rather than hidden inside the tool above. Replace them with your own numbers and the same arithmetic applies — nothing about the method changes, only the inputs feeding it.
Reading the result
When YTM exceeds current yield the bond is trading below face value and part of the return arrives as a capital gain at redemption. When it is lower, you are paying a premium that erodes towards par.
Where this goes wrong. YTM assumes every coupon is reinvested at the same yield. In practice they are reinvested at whatever rates prevail, so the realised return differs — this is reinvestment risk, and it grows with the term.
A useful check on any unfamiliar result is to compare it against a rough mental estimate first — round the inputs to convenient numbers and see whether the calculator's answer lands in roughly the same territory. A wildly different figure usually means one of the fields was entered in the wrong unit, most often a percentage typed as a whole number where a decimal was expected, or the reverse.
Only if you hold to redemption, the issuer pays in full, and you reinvest each coupon at the same yield. The first two are usually reliable for government bonds; the third almost never holds exactly.
The same calculation run to the earliest date the issuer can redeem early. For callable bonds trading above par, assume the call: issuers refinance as soon as it is cheaper for them, not for you.
The headline figure is yield to maturity (approx.). With 1,000 face value, 920 market price and 4.5 % coupon rate, that comes to 6.076 %. Change any field and the figure moves with it.
Whenever one of the underlying figures changes — a new interest rate, a different balance, an updated term — since the result only reflects what is currently in the fields. There is no need to keep a separate record of past results; the web address for a filled-in version already carries the figures used to produce it.
Not unless a tax rate or a fee is explicitly one of the inputs above. Where it is not, the figure shown is a gross calculation, and any tax due depends on your personal circumstances and current tax rules, which are worth checking separately.
The arithmetic itself is exact — the calculator applies the formula shown above precisely, with no rounding until the final figure is displayed. The uncertainty, where it exists, is entirely in the inputs: an estimated rate or an approximate balance carries that same approximation through to the result.