Practical guides, how-tos and comparisons to get the most out of our free online tools.
The number on the farm's front page is a gross figure before every subtraction. Here is a 120 percent APY walked down, one layer at a time, to the 33.6 percent that actually landed — plus why APR and APY are not the same number.
Camille Laurent · 7 min read
Percentage of promoters minus percentage of detractors. Passives sit in the denominator and nowhere else, the result runs from −100 to +100, and it is not a percentage despite looking like one.
Camille Laurent · 8 min read
One half-life leaves 50%, three leave 12.5%, ten leave less than a tenth of a percent. The formula is a single line — the part worth understanding is why the answer never reaches zero.
Lena Hoffmann · 8 min read
Count wallpaper rolls correctly when the pattern repeats: how repeat length creates waste on every strip, and how to turn wall area into the number of rolls to buy.
Marco Bianchi · 4 min read
A pound of body fat holds about 3,500 calories. See where the number comes from, why it's a rough guide, and how to use it for weight loss.
Sofia Nunes · 2 min read
Add up energy, water, heating, and maintenance with simple rules of thumb so you know what a home really costs to run each month.
Camille Laurent · 5 min read
An advertised $32,000 car leaves the lot at $36,399 before any trade-in — $2,324 of sales tax, $500 of doc fee, $375 of title and registration and $1,200 of add-ons. Strip the add-ons and the irreducible gap is $3,115, or 9.73 percent of the sticker.
Camille Laurent · 13 min read
Engagement rate is not one metric. Divide by followers, by reach or by impressions and the same post returns three different numbers — and every platform defaults to a different denominator.
Camille Laurent · 9 min read
A US cup holds 8 fluid ounces, a pint 16, a quart 32, and a gallon 128. See the full chart with milliliter equivalents and why US and UK ounces are not the same.
Marco Bianchi · 3 min read
How many calories does swimming burn? Learn the MET-based formula, typical MET values for freestyle, breaststroke, backstroke, and butterfly, and how weight and effort change the total.
Aisha Karim · 4 min read
A twelve-year-old roof that costs $20,000 to replace is worth $10,400 on a straight-line schedule. After a $2,000 deductible, an actual cash value policy pays $8,400 and a replacement cost policy pays $18,000 — same roof, same loss, $9,600 apart.
Camille Laurent · 12 min read
A $3.30 plate on a $12.00 menu is 27.5 percent. An extra 30 grams of chicken and 6 percent waste push it to 31.65 percent — while a 5 percent supplier increase moves it only 1.38 points.
Camille Laurent · 8 min read