Savings & financial mathematics
Cash Reserve Runway: Measure the Spending Gap, Not Just Monthly Bills
Find how many months accessible savings can cover your actual spending gap, then identify the first bill date that could fail.
Financial education
Savings & financial mathematics
Contribution schedules, compounding, fees and purchasing power.
Analysis & practical guides
47 articles
Savings & financial mathematics
Sinking Funds for Planned Expenses: Save Against a Known Payment Date
Turn a dated bill into a per-payday transfer, check whether that transfer fits, and repair the plan when a deposit is missed.
Savings & financial mathematics
Emergency savings, cash flow and money you may need soon
Calculate how long a USD reserve can cover essential costs, test a withdrawal and higher expenses, and build a dated replenishment plan.
Savings & financial mathematics
Why Two Day-Count Conventions Produce Different Bond Settlement Interest
Audit the numerator, denominator and settlement boundary before treating an accrued-interest difference as an error.
Savings & financial mathematics
A Treasury Bill Discount Rate and a Savings Yield Use Different Bases
Convert face-based discount quotation into cash paid and holding-period return before comparing unlike annual rate labels.
Savings & financial mathematics
Will a More Efficient Freezer Recover Its Higher Purchase Price?
Translate energy-use differences into a purchase premium threshold while accounting for lifespan and cash opportunity cost.
Savings & financial mathematics
Allocate Monthly Savings Between a Fixed Deadline and a Flexible Goal
Fund the minimum dated commitment first, then compare how much flexibility remains for a second goal.
Savings & financial mathematics
Audit a Six-Month Savings Offer for Rate Units, Holding Period, and Charges
Normalize an annual effective yield into the actual holding period, subtract stated dollar costs once, and compare the gain with an existing account.
Savings & financial mathematics
Designing a Child's Savings Match with a Clear Family Spending Cap
Calculate a bounded parental match, distinguish it from account interest, and let the child practice tradeoffs without creating an open-ended household promise.
Savings & financial mathematics
Compounding Frequency: What Changes When Interest Is Added More Often
Understand how compounding intervals change a savings balance, why the nominal rate must stay constant, and when account comparisons need a different approach.
Savings & financial mathematics
Nominal Rates and Effective Annual Yields Are Different Measurements
Translate nominal interest into an effective annual yield, compare equivalent annual growth, and avoid counting the same compounding benefit twice.
Savings & financial mathematics
Simple and Compound Interest: The Base That Earns Interest Matters
Compare simple and compound growth by following the interest base, separating distributions from reinvestment, and testing a clear savings example.