Blog ToolSelf
Guides sur la fiscalité, la finance, les affaires et les outils pratiques pour freelances et tout le monde.
Project Profit Calculator: Are You Actually Making Money?
Many freelancers underestimate project costs. Here's how to factor in time, tools, taxes, and overhead to find your real profit margin.
BMI Explained: What Your Body Mass Index Actually Means
BMI is a quick screening tool but not a diagnosis. Here is what the WHO categories mean, when BMI fails, and what to do with your number.
Water Intake: Is 8 Glasses a Day Actually a Rule?
The "8 glasses" rule has no scientific basis. Real hydration needs depend on body size, climate, activity and diet.
Depreciation: Deduct Equipment & Assets Over Time
Equipment loses value over time, and you can deduct that depreciation. MACRS and straight-line depreciation explained.
The True Cost of a Hire: More Than Just Salary
When you hire an employee, the total cost is much higher than the salary. Include taxes, benefits, and overhead.
JSON Format Mastery: Beyond Just Adding Spaces
A formatter is more than indentation. The good ones validate, surface schema issues, and minify on demand.
Password Strength: Why "P@ssw0rd!" is Weak Despite Looking Strong
Rule-based password validators are gameable. Entropy-based checkers (zxcvbn) catch what character-class rules miss.
Regex Cheatsheet: 12 Patterns That Cover 80% of Cases
Email, URL, phone, IP, hex color, datetime, UUID — bookmark these proven patterns instead of re-inventing them.
Quarterly Taxes: The Guide Freelancers Need
Most freelancers owe quarterly taxes. Missing a payment costs penalties and interest. Here's the timeline and how to calculate what you owe.
Capital Gains Tax: Understanding Long-Term vs Short-Term
Selling investments? Capital gains tax rates depend on how long you held the asset. Long-term gains are usually taxed at lower rates.
GPA Calculation: Weighted, Unweighted, and Why It Matters
Unweighted GPA tops out at 4.0. Weighted GPAs reward AP/IB courses. Colleges typically recalculate to their own scale.
Favicon Generator: The 7 Files Every Site Needs
A modern favicon is not one file — it is a set of ICO, PNG and SVG variants for different browsers and devices.