What is Bond Duration?
Bond duration is a measure of how sensitive a bond's price is to changes in interest rates. It represents the weighted average time until a bondholder receives all of the bond's cash flows. Duration is expressed in years and is a crucial tool for managing interest rate risk.
Types of Duration
Macaulay Duration
Named after economist Frederick Macaulay, this measures the weighted average time until a bond's cash flows are received. The weights are the present values of each cash flow divided by the bond's price.
Modified Duration
Modified duration adjusts Macaulay duration to estimate how much a bond's price will change for a 1% change in yield. It's calculated by dividing Macaulay duration by (1 + yield/payment frequency).
How to Use This Calculator
- Enter the bond's face value (par value)
- Enter the annual coupon rate as a percentage
- Enter the yield to maturity (YTM)
- Enter the years remaining until maturity
- Select how often coupon payments are made
- Click "Calculate" to see the results
Understanding the Results
- Macaulay Duration: The weighted average time to receive cash flows in years
- Modified Duration: The percentage price change for a 1% yield change
- Bond Price: The present value of all future cash flows
- Price Change Estimate: Shows how much the price would change if yields move up or down by 1%
Key Concepts
- Higher duration means greater price sensitivity to interest rate changes
- Zero-coupon bonds have duration equal to their maturity
- Lower coupon rates lead to higher duration
- Longer maturities typically mean higher duration
Frequently Asked Questions
How accurate are the results?
The Bond Duration applies a standard formula to your inputs — accuracy depends on how precisely you measure those inputs. For planning and estimation, results are reliable. For high-stakes or professional decisions, cross-check the output with a domain expert or primary source.
Should I include inflation in my inputs?
Depends on your goal. For comparing investments head-to-head, nominal rates are fine. For projecting real purchasing power, use real (inflation-adjusted) rates — typically nominal rate minus ~3% for long-term US inflation.
Common Tip Percentages
| Service | Typical Tip Range | Notes |
|---|---|---|
| Restaurant (sit-down) | 15–20% | 20%+ for exceptional service |
| Food delivery | 10–20% | Consider extra for long distances |
| Taxi / rideshare | 10–20% | More for assistance with luggage |
| Hotel housekeeping | $2–5/night | Leave daily, not just at checkout |
| Barber / hair salon | 15–20% | On pre-discount total |
| Pizza delivery | 10–15% or $3–5 minimum | Higher in bad weather |
General Household Budget Ratios (50/30/20 Rule)
| Category | % of Net Income | Examples |
|---|---|---|
| Needs | 50% | Rent, groceries, utilities, insurance |
| Wants | 30% | Dining out, entertainment, hobbies |
| Savings / Debt | 20% | Emergency fund, retirement, extra payments |
Common Measurement Conversions for Everyday Use
| Quantity | US / Imperial | Metric Equivalent |
|---|---|---|
| 1 cup | 8 fl oz | 237 mL |
| 1 pint | 16 fl oz | 473 mL |
| 1 quart | 32 fl oz | 946 mL |
| 1 gallon | 128 fl oz | 3.785 L |
| 1 lb | 16 oz | 453.6 g |
| 1 ft | 12 in | 30.48 cm |