XIRR vs YTM: Why Your Bond Return Doesn't Match the Quoted Yield
You bought a bond quoted at an 8.2% YTM. Six months later you ran XIRR on your actual cash flows in a spreadsheet and got 8.6%. Neither number is wrong — they answer slightly different questions, using different compounding conventions. Here's exactly where the gap comes from.
What YTM actually measures
Yield to Maturity is the single discount rate that, when applied to a bond's remaining coupon and principal cash flows, makes their present value equal the bond's current price. By long-standing market convention, YTM is quoted as a nominal annual rate on a bond basis — for a semi-annual coupon bond, the market halves the annual rate and compounds twice a year, regardless of the actual number of days between coupon dates.
See What is YTM, Really? for the full discount-rate mechanics this builds on.
What XIRR actually measures
XIRR (as implemented in Excel/Google Sheets and used for the calculators on this site) solves for the single annualized rate that makes the net present value of a series of dated cash flows equal zero. It uses actual calendar dates for every cash flow and compounds on an actual/365 day-count basis — no bond-basis convention, no assumption of exactly equal coupon periods.
The core difference: compounding convention
| Factor | YTM | XIRR |
|---|---|---|
| Compounding basis | Bond basis — fixed periods (semi-annual, quarterly) | Actual/365 — real calendar days between flows |
| Cash flow dates | Assumed evenly spaced from settlement | Exact dates you enter, however irregular |
| Reinvestment assumption | Coupons reinvested at the same YTM (a modelling assumption, not a guarantee) | No reinvestment assumption — measures return on the cash flows as they actually occurred |
| Typical use | Comparing bonds on a screener at the point of purchase | Measuring your own realized/expected return on an actual holding |
Worked example
Say you buy a 5-year, 8% annual-coupon bond with ₹100 face value, 47 days into the current coupon period, at a clean price of ₹98.50. The bond's quoted YTM on a bond-basis calculation might come out to 8.32%.
Now run XIRR on your actual cash flows: the purchase outflow on today's exact date (including the accrued-interest dirty price you actually paid), then each future coupon and the final redemption on their exact calendar dates. Because the first coupon period is shorter than a full year from your purchase date, and XIRR uses actual/365 day counts rather than the bond-basis assumption, the XIRR figure typically comes out slightly different from the quoted YTM — the direction and size of the gap depend on where in the coupon cycle you bought and the exact day-count difference for that period.
Neither figure is "more correct" in isolation — YTM is the standardized, comparable number the market quotes; XIRR is the return arithmetic on your specific, dated cash flows.
When to use which
- Use YTM when comparing bonds against each other on a screener, at the point of purchase — it's the standardized convention every quote uses, so comparisons are apples-to-apples.
- Use XIRR once you actually hold the bond and want to measure your realized or projected return based on your specific purchase date, price paid, and the exact dates you'll receive cash flows.
Quick reference
| Question | Metric to use |
|---|---|
| Which bond has the better quoted return? | YTM |
| What return will I actually earn on my specific purchase? | XIRR |
| Comparing across a screener list | YTM |
| Tracking your own portfolio's performance | XIRR |
Key takeaways
- YTM and XIRR both estimate a bond's annualized return but use different compounding conventions — YTM on a fixed bond basis, XIRR on actual calendar dates.
- A gap between the two on the same bond is expected, not an error — it comes from day-count and period-length differences, not different investment quality.
- Use YTM to compare bonds before buying; use XIRR to measure the actual return on cash flows you've already committed to specific dates.
Related reading: What is YTM, really? · Accrued interest and dirty price · Compare bond yields on the screener →