Practical guides, how-tos and comparisons to get the most out of our free online tools.
The turnover rate is an argument about the denominator, and the same year of data gives anything from 11.4% to 16.5%. Then the cost — built from vacancy, recruitment, onboarding and the ramp, not from a quoted multiple of salary.
Camille Laurent · 11 min read
Monthly recurring revenue is a normalised run rate, not revenue earned. Normalise it wrong and every downstream number is wrong. Here is the movement analysis that explains the figure, and why net revenue retention decides whether growth compounds.
Camille Laurent · 11 min read
Takt is demand, cycle time is capability, lead time is what the customer experiences. Confusing them is the most common failure in a first improvement project — and Little's Law is the bridge from one to the next.
Camille Laurent · 12 min read
Gross margin return on inventory investment divides gross margin by the cash tied up in stock. It exists because margin alone ranks products wrongly: a 60% margin turning twice a year loses to a 25% margin turning twelve times.
Camille Laurent · 11 min read
Between the price on the product page and the money in the bank sit seven deductions, one of which is charged per order rather than per euro. Walk one order down the ladder, then compute the return rate at which the whole thing goes negative.
Camille Laurent · 11 min read
Gross margin nets off cost of goods sold; contribution margin nets off only the costs that vary with the unit. The gap decides your break-even, your operating leverage, and how much extra volume a price cut really needs.
Camille Laurent · 13 min read
The relationships behind 60 seconds, 60 minutes, 24 hours and 86,400 seconds a day, with quick conversions you can reuse.
Lena Hoffmann · 3 min read
Find the exact days to your next birthday, including the tricky case where this year's date has already passed.
Lena Hoffmann · 4 min read
An exponent is repeated multiplication. Learn the laws of exponents, what negative and fractional powers mean, and why anything to the zero is one.
Lena Hoffmann · 3 min read
Most adults read prose at about 200-250 words per minute. Learn what a normal reading speed is, how to measure yours in a minute, and why comprehension matters more than raw speed.
Daniel Okonkwo · 4 min read
Understand data units clearly: the 1024-vs-1000 split, bits versus bytes, and why a 1 TB drive shows as roughly 931 GB — with real file and storage sizes.
Daniel Okonkwo · 3 min read
Percent error tells you how close a measurement is to the true value. Learn the formula, work through an example, and see how scientists use it to judge accuracy.
Lena Hoffmann · 3 min read