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From the Blog
Guides and explainers to help you make better decisions.
Caffeine Half-Life: How Long Coffee Stays in Your System (My 3 p.m. Flat White Was Still Awake at Midnight)
Caffeine's half-life is about 5 hours, so a 3 p.m. coffee is still a third in your system at 11 p.m. See the formula, worked examples and your cutoff time.
Stopping Distance on Snow and Ice: I Braked at the Same Spot I Always Do and Slid 80 Feet Past the Stop Sign
Stopping distance on snow and ice can be 2–10 times longer than on dry roads. See the formula, real numbers at 30, 45 and 60 mph, and what speed is safe.
Standard Deduction vs Itemizing in 2026: How to Know Which One Actually Saves You More
Standard deduction vs itemizing for 2026: the new $16,100 and $32,200 amounts, a worked Schedule A example, and a year-end bunching trick that can save hundreds.
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