For bonds and bond funds, computing prices and yields can be tricky. When rates go up prices go down and vice versa.

To determine where you stand for different prices and rate scenarios, use the calculator below.

For an individual bond, enter the bond's coupon rate and maturity date. If you then enter a price, the calculator will display the bond's yield to maturity; if you enter a yield, the calculator will show you the corresponding price.

For a bond fund, the calculation requires some imaginative thinking. For "coupon rate" enter the fund's yield and use the average weighted maturity from your fund's prospectus to create a maturity date for the fund. (Yes, we know, most bond funds don't mature, but the average maturity of all bonds in the fund gives you a functional fund maturity.)

Then, enter 100 for price. The fields "coupon rate" and "yield" should be equal. Adjust the yield to see the percent change in price. You can also use the sliders to see the effects of price and yield changes.

Note that prices are written in the standard bond format, where 100 means face value, 90 means 90% of face value, and so on.

Read on for how to use this bond calculator to stress test your bonds. You can also get more in our bond primer.