Tools

1 MPa = 10 bar = 145 psi. The pressure-unit matrix, which industry uses which, and mental-math shortcuts for tires, scuba, and hydraulics.

kJ and kcal measure the same energy in different units. The 4.184 ratio, the Calorie/calorie confusion on labels, and three mental shortcuts.

SBA, IRS e-file, USCIS, Common App, FAFSA each cap PDF size differently. Platform-specific limits plus xconvert settings that fit each.

WebM (VP9/AV1) is 30-50% smaller than MP4 H.264 at equivalent quality. When to use it, trade-offs vs MP4, and exact xconvert settings.

iPhones and modern Androids record HEVC by default. How to shrink HEVC file size without re-encoding to H.264 – keep the format, save storage.

PNG, WebP, AVIF, and JPG each have a sweet spot. The decision framework, size vs quality vs compatibility, for web, print, and chat sharing.

Office-scanner TIFFs hit 30-100 MB. Compress or convert to PDF/JPG for email, keeping text crisp and signatures legible.

EV makers publish power in HP and kW – Tesla in HP, Mercedes EQ in kW. The conversion, why electric HP differs, and what kW means for charging.

European car specs list power in kW; US specs use HP. The formula, a conversion table by model, and the mechanical-vs-metric-HP difference.