Many free calculators covering fixed income, investment performance, mortgage financing and personal finance. Each is built to match how the underlying instrument works in professional practice – not a simplified consumer version. No signup required.
Most online financial calculators are built for quick estimates, not accurate analysis. They omit inputs that actually matter – like settlement dates, day-count conventions, and coupon frequency – in favour of asking for the YTM directly, which defeats the purpose of using a calculator.
The calculators on this site take a different approach:
Professional input model. The bond calculators use the same six inputs – nominal value, maturity date, settlement date, clean price, coupon rate and coupon frequency – that practitioners actually have available from a bond’s term sheet or broker confirmation. The calculators derive everything else internally, including accrued interest, dirty price and YTM.
Worked examples with real numbers. Every calculator page includes a step-by-step worked example with specific inputs and outputs, so the math is verifiable and the methodology is transparent.
Honest limitations. Every metric has assumptions and edge cases where it breaks down. The Sharpe ratio penalises upside volatility. Modified Duration assumes linear price-yield relationships. IRR assumes reinvestment at the IRR itself. These limitations are explained, not hidden.
Built by a finance professional. Every calculator on this site is designed by Fil J., a finance professional with over six years of experience across financial market supervision, corporate finance and portfolio management.
The strongest cluster on this site. Six professional-grade calculators covering bond pricing, yield, duration and repo mechanics. The fixed income content here goes deeper than almost any free resource online because it is built to match how institutional bond markets actually operate.
Calculate accrued interest and dirty price for any bond. The foundational calculation for all bond settlement and yield analysis. Six inputs, handles odd coupon periods automatically, supports Actual/Actual day count convention.
Calculate YTM for any coupon bond using Newton-Raphson iteration. Handles semi-annual, annual and quarterly coupon frequencies. Produces YTM accurate to 0.0001 – settlement grade precision.
Yield calculation for bonds with no periodic coupons. Uses the direct closed-form formula since zero-coupons have a single cash flow at maturity. Useful for STRIPS, T-bills and any discount-priced security.
Calculate both Macaulay Duration (the time-weighted average of cash flows) and Modified Duration (the percentage price change per 1% yield move). The standard measures for fixed-rate bond interest rate risk.
For callable bonds, putable bonds, and any instrument with embedded options. Numerically calculates duration by repricing the bond at shifted yields rather than assuming fixed cash flows. The correct tool when Modified Duration would mislead.
Calculate settlement value, repo interest and repurchase amount for any repo transaction. Bond-specific inputs including coupon schedule, accrued interest and haircut analysis. Used by professional traders for verifying repo confirmations.
Risk-adjusted return metrics and discounted cash flow analysis tools.
The standard risk-adjusted return metric. Excess return per unit of total volatility. The first stop in evaluating any investment strategy or portfolio.
The downside-only version of Sharpe. Uses lower partial moments to measure downside risk specifically, rather than total volatility. More honest for asymmetric strategies like options or hedge funds where upside volatility is desirable.
Net Present Value and Internal Rate of Return for any investment cash flow series. Supports unlimited cash flow periods. The standard tools for project evaluation, real estate analysis and corporate finance decisions.
Practical calculators for the financial decisions most people face – mortgages, leases and savings.
Monthly payment, total interest, and complete amortisation schedule for any mortgage. Shows the front-loaded interest distribution that surprises most borrowers (in year one of a 30-year mortgage, 86% of each payment goes to interest).
Direct side-by-side comparison of 30-year and 50-year mortgage terms. Shows the exact monthly cost difference and total interest difference for any loan amount and rate.
Calculate monthly lease payment, money factor (the disguised interest rate dealers use), and total lease cost. Includes money factor to APR conversion – one of the most useful and poorly-explained concepts in consumer finance.
Compound interest calculation for any savings strategy. Model how regular contributions, interest rate and time horizon combine to build long-term wealth.
Different financial questions require different tools. Quick decision guide:
“I’m buying a bond – what will it actually cost to settle?”
Start with the Accrued Interest & Dirty Price Calculator. The dirty price is the actual settlement amount.
“I’m comparing bond yields across different prices and maturities.”
Use the Coupon Bond YTM Calculator for coupon bonds or the Zero-Coupon Calculator for zero-coupons.
“How much will my bond portfolio lose if rates rise 1%?”
Use the Macaulay & Modified Duration Calculator. For callable bonds or MBS, use the Effective Duration Calculator instead.
“I’m financing bonds through repo – what are the cash flows?” The Repo Calculator handles all repo transaction mechanics including haircuts.
“How good is my portfolio’s risk-adjusted performance?”
Start with the Sharpe Ratio Calculator. For strategies with asymmetric returns, also run the Sortino Ratio.
“Should I take this investment opportunity?”
The NPV & IRR Calculator gives you both metrics from the same cash flow series.
“Can I afford this mortgage?”
The Mortgage Calculator shows monthly payment and total interest. Run the 30 vs 50 Year Comparison before choosing a term.
“Is leasing a car a better deal than buying?”
The Lease Calculator shows the true cost of leasing including the money factor markup most dealers do not disclose.
“How much will my savings grow over time?”
The Savings Calculator models compound growth from regular contributions.
Yes. Every calculator on the site is free to use without registration, signup or paywall. The site is funded through unobtrusive display advertising. There are no premium versions or hidden features.
No. Each calculator page includes a step-by-step worked example using realistic numbers, plus interpretation guidance for the results. The pages are designed to be useful at three levels: finance students learning the concepts, retail investors making decisions, and working professionals verifying calculations.
Currently the calculators do not include save or export functionality. Each calculation is performed in your browser session. For documentation purposes, screenshot the inputs and outputs, or copy the numerical results to your own records.
Yes. The calculators are designed for accurate professional analysis. Citation as a reference source is welcomed. The underlying methodology is documented on each calculator page so results can be verified and reproduced.
Calculator outputs use industry-standard formulas and conventions. Bond calculations use Actual/Actual day count. YTM is calculated to four decimal places using Newton-Raphson iteration. For exact reconciliation against Bloomberg or broker quotes, day-count convention assumptions should match documented on each calculator page.
The site is continuously developed. Recent additions and improvements:
New calculators are added based on what readers find most useful. Suggestions are welcomed – use the contact form to request new tools or features.
The calculators are paired with detailed professional articles explaining the underlying concepts:
Bond Accrued Interest & Dirty Price Explained
Repo vs Reverse Repo Explained
Internal Rate of Return (IRR) Explained
Net Present Value (NPV) Explained
Each calculator page also links to the relevant deeper article in its “Deeper Reading” section.