Guides & Articles

Practical, number-driven guides that pair with our calculators — no fluff, working shown. 78 guides across 10 topics.

Finance

All 20 finance guides →
Simple Interest vs Compound InterestAug 30, 2026 · 6 min readPaycheck Taxes by State: All 51 ComparedAug 26, 2026 · 12 min readNo Income Tax States: What You Actually SaveAug 22, 2026 · 7 min readWhat Will My Car Payment Be?Aug 20, 2026 · 6 min read

Health

All 12 health guides →
When to Take a Pregnancy Test (and What hCG Levels Mean)Aug 31, 2026 · 6 min readHow Many Calories Should You Eat to Lose Weight?Aug 14, 2026 · 4 min readWhen Did I Conceive? Working Back From a Due DateAug 14, 2026 · 4 min readWhat Time Should I Go to Bed?Aug 12, 2026 · 5 min read

Construction

All 10 construction guides →
Stair Rise and Run: Getting the Numbers RightAug 27, 2026 · 7 min readHow Many Fence Posts Do I Need?Aug 26, 2026 · 6 min readHow Many Bricks Per Square Foot?Aug 21, 2026 · 6 min readHow Many Squares of Shingles Do I Need?Aug 19, 2026 · 7 min read

Conversion

All 10 conversion guides →
US Time Zones Explained: EST, CST, MST, PST and UTCAug 29, 2026 · 6 min readHow Many Miles Is a 10K?Aug 28, 2026 · 5 min readEST vs EDT: The One-Hour Mistake Almost Everyone MakesAug 25, 2026 · 6 min readWhy a Cup of Flour Is Never the Same TwiceAug 18, 2026 · 5 min read

Everyday

All 7 everyday guides →
How Many Pizzas Do I Need?Sep 1, 2026 · 5 min readHow to Calculate Your Exact Age (Leap Years Included)Aug 8, 2026 · 4 min readBusiness Days vs Calendar DaysAug 1, 2026 · 5 min readMinutes to Decimal Hours: The Payroll Conversion ChartJul 29, 2026 · 4 min read

Business

All 6 business guides →
GST and Reverse Charge Invoices: What Must Be on the PageAug 24, 2026 · 8 min readUS Invoice Rules: Sales Tax and the New 1099 ThresholdAug 21, 2026 · 6 min readROI vs Annualized Return: Why a 60% Gain Can Be MediocreJul 31, 2026 · 5 min readWhy 20% Then 10% Off Is Not 30% OffJul 30, 2026 · 5 min read

Electrical

All 5 electrical guides →
How Many Solar Panels Do I Need to Power a House?Aug 6, 2026 · 5 min readWhat Size AC and Generator Do You Actually Need?Jul 27, 2026 · 7 min readWhat Wire Size Do I Need for a Long Run?Jul 20, 2026 · 5 min readWhat Does It Cost to Run an Appliance?Jul 10, 2026 · 6 min read

Math

4 guides
How to Simplify a Square RootSep 2, 2026 · 5 min readHow to Calculate Percentage Increase and DecreaseJul 7, 2026 · 5 min readMean, Median and Standard DeviationJun 29, 2026 · 6 min readHow to Add Fractions With Different DenominatorsJun 22, 2026 · 6 min read

Other

2 guides
What Actually Makes a Password StrongAug 9, 2026 · 7 min readHow Old Is My Dog in Human Years?Jun 17, 2026 · 6 min read

Gaming

2 guides
What Is eDPI, and What Should Yours Be?Aug 23, 2026 · 5 min readWhat Is a Good KD Ratio?Aug 17, 2026 · 5 min read