Explainers
Why two calculators disagree, where a formula comes from, and which convention a number was computed under. Every figure here is produced by the engine that serves the calculator it links to.
The 15-year mortgage saves $255,518. That is the easy half
On $300,000 the shorter loan saves a quarter of a million in interest. Whether it leaves you better off depends on one number, and the usual comparison gets that number wrong.
Ten double-spaced pages is five single-spaced pages
Double spacing exactly halves the words on a page, so the conversion is a factor of two. The harder question is how many words a page holds at all, and that depends on the font.
Your 1 TB drive is not missing 69 GB
A new 1 TB drive reports 931 GB and nothing is wrong. The manufacturer and the operating system are counting in different bases, and both are telling the truth.
A raise cannot leave you worse off
Crossing into a higher tax bracket taxes the next dollar more, not every dollar. On a $1,000 raise at the 22% to 24% boundary you keep $762.