Guides
Practical guides for finance, health, tax, and time calculations. Page 5 of 6.
How Much Should I Weigh for My Height? The Answer
Find your healthy weight range by height using BMI, the Hamwi formula, and Devine's method — with real examples for men and women and what the formulas can't tell you.
FinanceIs Buying an Electric Car Worth It? The Real Math
Compare EV energy and ownership costs with explicit assumptions, no assumed purchase rebate, and the US federal credit acquisition cutoff.
HealthHow Many Calories a Day Do You Need to Lose Weight?
Understand an adult Mifflin-St Jeor energy estimate, activity assumptions and why a calorie adjustment cannot promise weekly weight loss.
FinanceIs It Worth Refinancing Your Mortgage? The Break-Even Math
Find out if refinancing your mortgage makes financial sense. Calculate your break-even point, monthly savings, and total interest saved — with real examples.
FinanceIs It Cheaper to Rent or Buy a House? The Real Math
Compare rent and ownership with equal budgets, separate investment earnings from contributions, and understand the first buying advantage.
Tax & BusinessHow to Calculate Your Take-Home Pay After Taxes
Estimate 2026 take-home pay with a shared-model example, distinguish tax liability from withholding and understand benefit and state-tax limits.
FinanceHow Compound Interest Grows Your Savings: Worked Examples
Compare a one-time deposit, monthly contributions and compounding frequency using reproducible examples, clear assumptions and a free calculator.
Tax & BusinessHow Is Capital Gains Tax Calculated on Stocks?
Short-term vs long-term rates, cost basis methods, and step-by-step examples — everything you need to estimate your capital gains tax bill.
FinanceHow Much House Can I Actually Afford? (The Reddit-Favorite Answer)
The 28/36 rule, the true cost of homeownership, and why online calculators give you different numbers — explained plainly.