Practical guides, how-tos and comparisons to get the most out of our free online tools.
Zakat is 2.5 percent of qualifying wealth held for a lunar year — but the threshold at which it becomes due has two classical definitions, one in gold and one in silver, and today they differ by roughly a factor of twelve. Here is why, and what each side argues.
Camille Laurent · 16 min read
Spending $40,000 a year needs $1,000,000 at 4 percent and $1,333,333 at 3 percent. Where the number came from, what it measured, and the four objections that matter.
Camille Laurent · 6 min read
Torque is the twisting force an engine makes; horsepower is how fast it does work. Learn the hp = torque × rpm ÷ 5252 link and why both numbers matter.
Marco Bianchi · 4 min read
Set a 300–500 kcal daily deficit to lose fat at a safe, sustainable rate while keeping muscle and training quality.
Aisha Karim · 4 min read
A $50,000 machine with a $5,000 salvage value and a five-year life. Straight line deducts $9,000 in year one, double declining balance $20,000, and MACRS $10,000. The lifetime total is the same; only the timing moves — and the timing is worth about $320.
Camille Laurent · 15 min read
Work out how much wine, beer and soft drinks to buy for a party. Plan on about one drink per guest per hour, then split the total between alcoholic and non-alcoholic options.
Marco Bianchi · 4 min read
To turn a step count into distance, multiply your steps by your stride length. Learn how to estimate your stride and convert steps into miles.
Sofia Nunes · 3 min read
Between roughly $1 and $10 per 1,000 views, and the reason the range is that wide is arithmetic, not luck. Here is every step from advertiser spend to your account.
Camille Laurent · 7 min read
Mileage reimbursement pays a set rate per mile driven for work. Learn how the rate is set, how the IRS, HMRC and URSSAF differ, and how to keep a compliant log.
Marco Bianchi · 4 min read
301 against 308, 302 against 307, 401 against 403, 404 against 410 — plus what Retry-After on a 429 or a 503 actually promises. The pairs where picking the wrong code changes behaviour, not just wording.
Daniel Okonkwo · 8 min read
Size a generator by listing the appliances you must run, adding their running watts, and allowing headroom for the surge when motors start.
Marco Bianchi · 4 min read
Renting vs buying, compared honestly: the break-even horizon, the opportunity cost of a down payment, and the situations where each option wins.
Camille Laurent · 3 min read