Formula-first financial guides
Practical breakdowns of the equations behind SBA loans, tax optimization, real estate underwriting, and investment math — written for business owners who want to understand the numbers.
Dividend yield and total return: the formula investors use to evaluate income stocks
A breakdown of the dividend yield, yield on cost, and total return equations that income investors use to compare securities — including DRIP compounding math and after-tax modeling.
How to calculate your SBA loan payment before you apply in 2026
A step-by-step walkthrough of the amortization formula lenders use to size SBA 7(a) payments — with worked examples at current Prime Rate.
SBA 7(a) vs. conventional business loan: which costs less over 10 years?
A side-by-side cost comparison of SBA 7(a) and conventional term loans — factoring in rate spreads, guarantee fees, and the real 10-year total interest paid.
SBA loan interest rates in 2026: current rates, caps & what they mean
Current SBA 7(a) max interest rate caps by loan size and term, tied to the April 2026 Prime Rate — and what the OBBBA changes mean for borrowers.
How to calculate compound interest: the formula, frequency, and real numbers
The exact compound interest formula — daily, monthly, and annual compounding compared with worked examples showing how frequency affects long-run growth.
Compounding frequency explained: daily vs. monthly vs. annual
How compounding frequency affects your final balance — with the math showing the real dollar difference between daily and annual compounding over 30 years.
How to calculate your mortgage payoff date with extra payments
The math behind accelerated mortgage payoff — how extra principal payments compress the amortization schedule and reduce total interest paid.
15-year vs. 30-year mortgage: total cost comparison with real numbers
A formula-first breakdown of the total interest difference between a 15- and 30-year mortgage — and which makes mathematical sense at different rate environments.
Early mortgage payoff strategies: bi-weekly payments, lump sums, and more
How bi-weekly payments, annual lump sums, and rounded payments each affect your payoff timeline — modeled mathematically so you can pick the right approach.
How to calculate the real impact of inflation on your purchasing power
Using the CPI formula to model how inflation erodes savings over time — with real vs. nominal return comparisons for cash, bonds, and equities.
Hedging against inflation in 2026: TIPS, I-bonds, and real assets
A mathematical look at inflation-hedging instruments — TIPS real yield, I-bond composite rate formula, and how commodities and real estate perform in inflationary cycles.
Real value vs. nominal value: why the difference matters for investors
How to convert nominal returns to real returns using the Fisher equation — and why ignoring inflation systematically overstates investment performance.
How to set savings milestones: the math behind realistic financial goals
Using the future value of annuity formula to reverse-engineer monthly savings targets from any financial goal — retirement, home purchase, or emergency fund.
High-yield savings vs. CD: which earns more at 2026 rates?
APY vs. APR, compounding differences, and a breakeven model showing when locking into a CD beats keeping cash in a high-yield savings account.
The psychology of saving money: why automating beats willpower
Behavioral finance research on savings inertia, present bias, and loss aversion — and the structural interventions that increase savings rates without requiring discipline.
How to calculate investment ROI: simple, annualized, and cash-on-cash
The three ROI formulas investors actually use — simple return, CAGR, and cash-on-cash — with worked examples showing when each metric is appropriate.
ROI vs. IRR: when simple return misleads and internal rate of return fixes it
Why ROI breaks down for investments with multiple cash flows — and how IRR solves the problem using the discount rate that sets NPV to zero.
Improving portfolio performance: rebalancing, fees, and tax drag
How expense ratios, trading costs, and tax drag compound to erode portfolio returns — and the mathematical case for low-cost index investing and annual rebalancing.
Savings vs. investing: how the math changes over different time horizons
A compound growth model comparing a HYSA, bonds, and a diversified equity portfolio over 5, 10, 20, and 30-year horizons — with inflation-adjusted real values.
Calculating your retirement number: the 4% rule and what it misses
How the 4% safe withdrawal rate is derived from sequence-of-returns modeling — and the adjustments needed for early retirees, longer horizons, and 2026 rate environments.
How to maximize your 401(k) in 2026: limits, match, and Roth vs. traditional
The 2026 401(k) contribution limits, employer match optimization math, and the break-even tax rate that determines whether Roth or traditional contributions win.
Roth IRA vs. traditional IRA: the tax math that determines which wins
The break-even marginal tax rate calculation that shows whether pre-tax or after-tax contributions produce more wealth at retirement — with 2026 income phase-out rules.
Debt snowball vs. avalanche: which method saves more money?
A mathematical comparison of snowball (smallest balance first) vs. avalanche (highest rate first) — showing exact interest saved and payoff timeline for each method.
Balance transfer vs. personal loan: the real cost comparison
How to model the true cost of a balance transfer (intro APR + fee + revert rate) vs. a fixed personal loan — with a break-even formula for each scenario.
How credit card interest is calculated: daily periodic rate explained
The daily periodic rate formula credit card issuers use to compute interest charges — and why the statement balance vs. average daily balance distinction matters.
Calculating gross, operating, and net profit margins: formulas and benchmarks
The three margin formulas every business owner needs — gross, operating, and net — with industry benchmark ranges and the common line items that erode each.
Markup vs. margin: why confusing them costs business owners money
The exact formulas for markup (cost-based) vs. margin (revenue-based) — with a conversion table and common pricing mistakes that result from conflating the two.
Strategies to increase profitability: price, volume, and cost levers
How the three profit levers — price increases, volume growth, and cost reduction — compare in impact using contribution margin math and sensitivity analysis.
ROI calculation methods: simple, annualized, and risk-adjusted returns
Simple ROI and annualized ROI answer different questions. This guide covers the formulas for both, a worked real estate example, benchmark comparison tables, and the most common variable mistakes that distort investment return calculations.
Profit margin formula: gross, operating, and net margin calculations
Gross margin, operating margin, and net margin are three mathematically distinct metrics that each measure a different layer of the income statement. This guide covers the formulas, a worked example, and industry benchmark ranges.
SBA loan amortization explained: how monthly payments are calculated
A step-by-step breakdown of the standard amortization formula that determines every SBA 7(a) loan payment, with worked examples using 2026 Prime Rate figures.
S Corp tax savings breakdown: the self-employment tax equation
How the S Corp election reduces self-employment tax liability through the reasonable salary and distribution split — with the exact FICA formulas behind the savings.
DSCR for real estate investment: what lenders calculate and why it matters
The debt service coverage ratio is the primary underwriting metric for investment property loans. This guide covers the formula, benchmark ranges, and how income and expenses shift the number.
Compound interest and long-term growth: the mathematics of exponential returns
Compound interest is the most fundamental concept in investment math. This breakdown covers the compound interest formula, the rule of 72, and how compounding frequency affects total accumulation.
Section 179 deduction and equipment cost modeling for business owners
The Section 179 deduction allows businesses to expense qualifying equipment in the year of purchase rather than depreciating it. This guide covers the 2026 limits, phase-out thresholds, and the tax savings formula.