Finance
56Loans, interest, investment and salary math.
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Guides & how-tos
Building & DIY
What Is a Board Foot? How to Measure and Buy Lumber
A board foot is a unit of volume equal to 144 cubic inches. Here's the formula, why nominal size (not actual) is used, a reference table of common boards, and how hardwood is priced per board foot.
Unit Converters
mcg vs mg: The Supplement Dosing Mistake to Avoid
1 mg equals 1,000 mcg, so mixing up micrograms and milligrams on a supplement label is a 1,000x error. Here's the conversion table, real vitamin doses (D, B12, folate, biotin), and how IU is different.
Fitness & Health
How the US Navy Body Fat Calculator Works (Tape Method)
The US Navy method estimates body fat from a few tape measurements: neck, waist, and height (women add hips). Here's the formula, how to measure correctly, how accurate it is versus DEXA, and the healthy ranges by sex.