Personal finance learning tool
Bond Duration Approximation Calculator
Approximate modified duration from estimated bond prices after equal yield increases and decreases.
Inputs and results stay in this browser. Currency symbols are illustrative; use any consistent currency.
Understand Bond Duration Approximation
One idea, three depths
Choose how deeply to explain Bond Duration Approximation
Bond Duration Approximation: Approximate modified duration from estimated bond prices after equal yield increases and decreases.
Age 5Explain it to a 5-year-oldStart with a picture
Imagine using Bond Duration Approximation to answer this question: approximate modified duration from estimated bond prices after equal yield increases and decreases? Enter Current bond price, Price if yield falls, Price if yield rises, and 1 other input; the calculator shows Approximate modified duration. Try changing one number and watch what happens to Approximate modified duration. The answer tells you Approximate modified duration.
Age 15Explain it to a 15-year-oldConnect it to the formula
Duration is a first-order sensitivity estimate; convexity and cash-flow changes matter for larger yield movements. The rule is Modified duration ≈ (price when yield falls − price when yield rises) ÷ (2 × current price × yield change). Its input values are Current bond price, Price if yield falls, Price if yield rises, Yield change (%), and the main result is Approximate modified duration. Try changing one number and watch what happens to Approximate modified duration.
CollegeExplain it at college levelState the model precisely
This calculator evaluates a personal-finance model from stated cash amounts, rates and time assumptions. The implemented relation is Modified duration ≈ (price when yield falls − price when yield rises) ÷ (2 × current price × yield change), evaluated from Current bond price, Price if yield falls, Price if yield rises, Yield change (%) to produce Approximate modified duration. Duration is a first-order sensitivity estimate; convexity and cash-flow changes matter for larger yield movements. The result cannot predict markets or include unentered taxes, fees, legal rules, benefits, insurance terms or personal circumstances. Verify material decisions against current documents.
What this personal finance tool does
Approximate modified duration from estimated bond prices after equal yield increases and decreases.
Why the relationship works
Duration is a first-order sensitivity estimate; convexity and cash-flow changes matter for larger yield movements.
The formula
Modified duration ≈ (price when yield falls − price when yield rises) ÷ (2 × current price × yield change)
Inputs and time periods
This model uses Current bond price, Price if yield falls, Price if yield rises, Yield change. Keep currencies and time periods consistent, and distinguish current known amounts from assumptions about future rates.
What the result means
The primary output is Approximate modified duration; supporting outputs include Approximate price change for 1-point yield rise, Price scenario spread. Compare scenarios by changing one input at a time.
Limits of this compact model
This educational calculator cannot predict markets or account for every tax, fee, legal rule, benefit, insurance policy or personal circumstance. Verify material decisions with current documents and qualified advice.
Supporting sourcesAcademic referencesPrimary standards, textbooks and complete citations
Standards, reading and academic references
Use the calculator as the worked interaction, then consult the primary standards and academic textbooks listed below. MW SysArc links to the original sources; the explanation on this page is original and does not reproduce them.
Principles of Finance
Read the free OpenStax finance textbookCite this book
- APA 7
- Dahlquist, J., & Knight, R. (2022). Principles of finance. OpenStax. https://openstax.org/books/principles-finance/pages/1-why-it-matters
- MLA 9
- Dahlquist, Julie, and Rainford Knight. Principles of Finance. OpenStax, 2022, https://openstax.org/books/principles-finance/pages/1-why-it-matters.
- Chicago author-date
- Dahlquist, Julie, and Rainford Knight. 2022. Principles of Finance. Houston, TX: OpenStax. https://openstax.org/books/principles-finance/pages/1-why-it-matters.
OpenStax entries are free to read online. Follow the licence shown on each linked source before redistributing or adapting its content.
Reuse the page responsiblyCite this pageAPA, MLA, Chicago, Harvard, BibTeX and RIS
These formats cite this calculator page itself. They are separate from the academic references above, which support the mathematical method and terminology.
APA 7
MW SysArc. (2026, July 21). Bond Duration Approximation Calculator. MW SysArc Tools. https://finance.mwsysarc.com/bond-duration-approximation
MLA 9
MW SysArc. “Bond Duration Approximation Calculator.” MW SysArc Tools, 21 July 2026, https://finance.mwsysarc.com/bond-duration-approximation. Accessed 31 Aug. 2026.
Chicago 17
MW SysArc. “Bond Duration Approximation Calculator.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://finance.mwsysarc.com/bond-duration-approximation.
Harvard
MW SysArc (2026) ‘Bond Duration Approximation Calculator’, MW SysArc Tools. Published 21 July 2026. Available at: https://finance.mwsysarc.com/bond-duration-approximation (Accessed: 31 August 2026).
BibTeX and RIS records
BibTeX
@misc{mwsysarc_bond_duration_approximation_2026,
author = {{MW SysArc}},
title = {Bond Duration Approximation Calculator},
howpublished = {MW SysArc Tools},
year = {2026},
url = {https://finance.mwsysarc.com/bond-duration-approximation},
note = {Published July 21, 2026; accessed August 31, 2026}
}RIS
TY - ELEC
AU - MW SysArc
TI - Bond Duration Approximation Calculator
T2 - MW SysArc Tools
PY - 2026
DA - 2026-07-21
Y2 - 2026-08-31
UR - https://finance.mwsysarc.com/bond-duration-approximation
N1 - Published July 21, 2026
ER -Clear answers
Frequently asked questions
What does the Bond Duration Approximation do?
Approximate modified duration from estimated bond prices after equal yield increases and decreases.
How does the Bond Duration Approximation work?
The calculator applies Modified duration ≈ (price when yield falls − price when yield rises) ÷ (2 × current price × yield change). Duration is a first-order sensitivity estimate; convexity and cash-flow changes matter for larger yield movements.
What can I learn from the Bond Duration Approximation?
You will connect Current bond price, Price if yield falls, Price if yield rises, Yield change to Approximate modified duration, then test how changing one assumption affects the financial decision.
Does MW SysArc receive or store what I enter?
No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.
How should I use the result?
Use the result as a planning reference, and review how income, expenses, irregular payments, rates and time periods were classified before making decisions.
Last reviewed . Calculations tested .