Blog
health
TDEE & Calorie Calculators: How to Actually Estimate Your Calories
TDEE calculators give a starting estimate ±10-15% accuracy. Learn the Mifflin-St Jeor formula, why every calc is an estimate, and the adaptive tracking method that actually works.
9 min read
health
Body Fat vs BMI: Which One Should You Actually Trust?
BMI cannot tell muscle from fat. See what BMI and body-fat percentage actually measure, where each one fails, and which to trust for your health.
7 min read
design
Cron Syntax Cheatsheet (2026): Read and Build Any Crontab Expression
Cron syntax explained: the 5-field order, a 10-second reading model, 16 verified recipes, the day-of-week OR gotcha, DST traps, and cron vs systemd timers.
10 min read
finance
Compound Interest Calculator vs a Savings Account: What Actually Grows Your Money
The formula, the APY that matters, and why a 0.38% bank account vs a 5% HYSA is a $462/year gap on $10k. Run the math before you pick.
9 min read
design
Regex Tester & Pattern Builder: A Practical Guide to Patterns That Actually Work
How to build regular expressions that actually work: anchors, quantifiers, the flavor traps across engines, and the ReDoS pattern that can hang your server. Test as you go.
9 min read
design
JSON vs YAML vs TOML: When to Pick Each (a Developer's Decision Guide)
JSON vs YAML vs TOML, decided: JSON for APIs and data, YAML for Kubernetes/CI config (mind the Norway problem), TOML for explicit app config like Cargo.toml. A clear decision guide.
9 min read
design
Base64 Encoding Explained: When and Why Developers Use It (and the Traps)
What Base64 does (3 bytes to 4 ASCII chars, +33% size), the real use cases (data URIs, JWT, Basic auth), and the traps: it is not encryption and not compression.
8 min read
design
Custom-Branded QR Codes: Add a Logo and Colors With a Free QR Code Generator
How error correction lets you overlay a logo on a QR code, the contrast and quiet-zone rules that keep it scannable, and the static-vs-dynamic catch.
8 min read
design
HEX to RGB to CMYK in 2026: Why the Print Color Never Matches the Screen
HEX to RGB is exact math. RGB to CMYK is a lossy guess that depends on the press, the paper, and an ICC profile. Here's the difference, the worked math, and where an online converter actually helps.
8 min read
design
Color Palette Tools for Accessibility: Why Most Palettes Fail Before You Ship
83.6% of homepages fail contrast. How to pick tools that verify accessible palettes, avoid common mistakes, and test the right combinations.
9 min read
design
WCAG Contrast for SaaS Dashboards: The 5-minute Audit That Catches Most Sins
Most SaaS dashboards quietly fail WCAG contrast on the metrics, sparklines, and disabled states nobody checks. Here's the cheatsheet, the failure patterns, and a 5-minute audit you can run today.
8 min read
health
Smart Scales for BMI Tracking in 2026: What's Worth the Wi-Fi
Smart scales sync your weight, body fat, and BMI to apps and dashboards — but the number on the screen is only half the story. Here's what to look for, what to ignore, and the limits of BMI itself.
9 min read
finance
Best Mortgage Calculators in 2026: Free, Paid, and the Five Inputs That Actually Matter
Most online mortgage calculators give you the wrong number because they leave out taxes, insurance, and PMI. Here's the five-input rule, the free tools that get it right, and when you actually need to pay.
9 min read
lifestyle
Tip-splitting Apps vs Free Tools: What's Actually Worth Installing in 2026
Splitwise, Tab, Tricount, and a dozen free web calculators all claim to fix the messy dinner bill. Here's where each one actually wins — and where simple math beats every app.
7 min read