Blog

V = IR, the triangle mnemonic, a worked LED current-limiting example, when Ohm's Law breaks down, and the three forms of the power equation (P=VI, P=I²R, P=V²/R).

Learn the difference between watts and kilowatt-hours, why BTUs persist in HVAC, and how the calorie on your food label is 1,000 times larger than the one in chemistry class.

Learn why an acre is 43,560 square feet, how it traces back to medieval ox ploughing, and how acres, hectares, and square feet compare for real estate and land measurement.

Learn why your 100 Mbps internet plan shows 12.5 MB/s downloads, what protocol overhead costs you, and how binary prefixes make your hard drive look smaller than advertised.

From a 16th-century rope with knots to the Parker Solar Probe, trace the history of speed measurement through chip logs, Mach numbers, and the sound barrier.

Learn why a '2% increase' in interest rates could mean $124,000 in extra mortgage payments or pocket change, depending on whether the headline means percentage points or percent change.

Learn why tire pressure is in PSI, bar, or kPa depending on where you live, how mmHg ended up as the blood pressure unit, and how to convert between all the common pressure units.

Learn why MPG, L/100km, and km/L measure the same thing in incompatible ways, how to convert between them, and why UK and US MPG numbers differ by 20% despite sharing a name.

Learn what BMI actually measures, why its categories were designed for populations rather than individuals, and how to interpret your number alongside waist circumference, body fat percentage, and other metrics.

Learn how compound interest turns $10,000 into $76,123 over 30 years, use the Rule of 72 shortcut, and understand why the same force that builds wealth can bury you in credit card debt.

Learn why your 1 TB drive shows only 931 GB, understand the decimal vs binary storage split, and see how much actually fits on a gigabyte or terabyte of storage.

From Galileo's thermoscope to the 2019 redefinition of the kelvin, trace four centuries of invention, rivalry, and revision behind the temperature scales we use today.

From NASA's $125 million Mars orbiter to a Boeing 767 that ran out of fuel mid-flight, these five real-world unit conversion disasters show why getting the units right matters.

Discover why measuring baking ingredients by weight instead of volume leads to more consistent results, and learn how to convert between cups, grams, and ounces.

Learn how mortgage amortization works, why most of your early payments go to interest, and strategies to pay off your home loan faster with extra payments.