Bond Price Change Calculator: Move Between Two Prices
Work out the percentage change between two bond prices — the headline mark-to-market move that captures how much rate shifts have pushed the bond's value.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Price change | Dollar change |
|---|---|---|
| $1,000 to $950 | -5.00% | -50 |
| $1,000 to $1,080 | 8.00% | 80 |
| $960 to $900 | -6.25% | -60 |
| $1,000 to $1,250 | 25.00% | 250 |
How This Calculator Works
Enter the earlier and current price for the same bond. The calculator subtracts one from the other for the dollar change and divides by the earlier price to give the percentage. The result is price-only return; add coupon income separately for total return.
The Formula
Percentage Change
Old is the starting value, New is the ending value
Worked Example
A bond falling from $1,000 to $950 is a 5% price decline — a $50 loss on a $1,000 face value bond. Long-duration bonds move much more than short ones for the same rate shift: a 1-point yield rise can move a 30-year Treasury down 15%+ in price, while a 2-year barely budges.
Key Insight
Bond price changes are inverse to yield changes — when yields rise, prices fall, and vice versa. The size of the move depends on duration: long bonds are sensitive (modified duration of 15+ years means a 1% yield change moves the price 15%+), short bonds are not. Investors looking at price changes alone underestimate bond total return; pair the percentage here with the coupon income for the real picture.
Frequently Asked Questions
How is bond price change calculated?
Subtract the earlier price from the current price, divide by the earlier price, and multiply by 100. A $1,000 to $950 move is a 5% price decline.
Why do bond prices change?
Primarily because of interest-rate shifts. When market yields rise, existing bonds fall in price (their fixed coupon becomes less attractive); when yields fall, existing bonds rise. Credit risk and inflation expectations also move prices.
Does this include the coupon?
No. The calculator measures price-only change. For total return, add the coupons received during the holding period to the dollar change before dividing by the starting price.
What is duration?
A measure of how sensitive a bond's price is to a 1% change in yield. A bond with modified duration of 10 moves about 10% in price for a 1% yield shift. Longer-maturity bonds typically have higher duration.
Why did my bond fund drop when I held to maturity?
Bond funds mark to market daily, so price moves show up in the NAV even though held-to-maturity individual bonds return par. Long-duration bond funds posted historic losses in 2022 when rates rose sharply — recovered in subsequent years as bonds in the portfolio matured.
Related Calculators
Data Sources & Benchmarks
This calculator draws on 1 independent, dated source.
Methodology & Review
The change is the new price minus the old; the percentage is that change divided by the old price. The figure captures price-only return; coupon income earned over the period is separate. Most bonds are quoted as a percentage of par value (e.g. 95.00 = 95% of par) — enter consistent units on both sides.
Written by Ugo Candido · Last updated May 17, 2026.