Guides
Longer explanations of the formulas behind our calculators, with worked examples you can check by hand.
Guide · 3 min readBMI vs Waist Size: Which Tells You More About Your Health?What BMI and waist circumference each measure, their official cut-offs, where BMI misleads, and how to use both together for a better picture of weight-related health risk.Guide · 2 min readCelsius and Fahrenheit: Quick Conversions for Cooking, Weather and FeverThe exact Celsius–Fahrenheit formulas, a mental shortcut, and ready-made tables for oven temperatures, weather and body temperature, with tips to avoid common mistakes.Guide · 3 min readHow Much House Can You Afford? The 28/36 Rule ExplainedUse the 28/36 rule to estimate an affordable mortgage payment from your income, turn that payment into a loan amount, and see what changes it: rates, debts, down payment and costs.Guide · 3 min readMbps vs MB/s: Why Your Download Is Slower Than Your Internet PlanWhy a 100 Mbps plan downloads at about 12 MB/s, what overhead, Wi-Fi and servers take away, how GB and GiB differ, and how to test your real speed properly.Guide · 3 min readHow to Calculate Fuel Cost for a Road Trip (Step by Step)A step-by-step method to estimate fuel for any road trip: find your real consumption, convert mpg and L/100 km, add a sensible margin and split the cost fairly.Guide · 2 min readWhy Does a 1 TB Drive Show Only 931 GB?The 'missing space' on new drives and phones explained: decimal gigabytes versus binary gibibytes, a conversion table for common sizes, and what else uses up storage.Guide · 3 min readTwo-Stroke Oil Ratios Explained: 50:1, 40:1, 32:1 and 25:1What two-stroke mix ratios mean, how to measure oil for any amount of fuel in litres or gallons, which oil to choose, and the mistakes that damage engines.