Plain-language explainers on how to calculate the numbers that matter — each paired with a free calculator so you can skip the math.
Markup and margin use the same profit but different bases. The two formulas, a conversion table, and a worked example so you never confuse them.
Why 3:1 is the benchmark, how to calculate the ratio from gross-profit LTV, and what a number that's too high or too low is telling you.
Gross vs operating vs net margin, typical benchmarks by industry, a worked example, and practical ways to improve the number.
Average rates by industry and channel, why revenue per visitor beats conversion rate alone, and how to lift the number.
The ROI formula, a worked example, how to annualize returns for fair comparison, and the limitations to keep in mind.
The definitions and formulas, when to use each, the four forces behind net new MRR, and why investors value recurring revenue.
The formula, a worked example, which margin to use, and when the benchmark actually applies to a software business.
Why break-even ROAS depends on your margin, what counts as good by business type, and how ROAS differs from ROI.
Why small churn reductions compound into big LTV gains, the common causes, and proven strategies to keep more customers.
The formula, a worked example, how it differs from net income, and the limitations to remember before relying on it.
Learn how to calculate your debt-to-income (DTI) ratio step by step, what counts as debt, the front-end vs back-end formula, and the DTI lenders want for a mortgage.
How much protein you need per day to lose weight, build muscle, or maintain — in grams per pound, with a worked example, timing tips, and GLP-1 considerations.
What counts as a good debt-to-income ratio in 2026, the DTI lenders want by loan type (mortgage, FHA, VA, auto), and where your number should land.
Practical, proven ways to lower your debt-to-income ratio before a mortgage or loan application — which debts to attack first and a realistic timeline.
How to calculate self-employment tax for 2026: the 15.3% rate, the 92.35% adjustment, the $184,500 Social Security wage base, and the deductible half — with an example.
How much water to drink each day based on your body weight, exercise, and climate — the simple formula, a worked example, and whether coffee and food count.
How much house you can afford based on your income, debts, and down payment — the 28/36 rule, what lenders approve, and a worked example.
The mortgage payment formula explained, what PITI means, and a worked example for a $300,000 loan — plus how rate, term, and extra payments change it.
How compound interest works, the formula, the Rule of 72, and why starting early matters — with a clear worked example you can follow.
How big your emergency fund should be, the 3–6 month rule, where to keep it, and how to build one fast — with a simple way to size yours.
What a $60,000 salary works out to per hour, month, and paycheck — the math, gross vs take-home, and a table of nearby salaries.
How overtime pay works under the FLSA — the time-and-a-half rule, who qualifies, and a worked example showing exactly how to calculate it.
What maintenance calories (TDEE) are, how to calculate them with the Mifflin-St Jeor formula and activity level, and how to set cut or bulk targets.
How to calculate your macros — protein, carbs, and fat — from your calorie target, with a worked example and how to adjust for fat loss or muscle gain.
Healthy body fat percentage ranges for men and women, the standard categories, how it differs from BMI, and how to measure and lower it.
Roth vs traditional IRA explained — the tax difference, when each one wins, income and contribution rules, and whether you can have both.
A healthy waist-to-hip ratio is 0.90 or below for men and 0.85 or below for women — what the number means, how to measure it, and how it compares to BMI.
What a good fat-free mass index looks like for men and women, the score ranges, the natural limit around 25, and how FFMI differs from BMI.
Good VO2 max values by age and sex, charts for men and women, and how to estimate and improve your aerobic fitness.
How many calories walking burns based on your weight, pace, and time — the MET formula, a calories-by-weight table, and tips to burn more.