Knots to km/h: The Conversion and Where Knots Are Used
One knot equals exactly 1.852 km/h and about 1.15 mph. See the exact conversion factor, why the nautical mile exists, and where aviation and shipping use knots.
Marco Bianchi · 4 min read
Guides & tutorials
Practical guides, how-tos and comparisons to get the most out of our free online tools.
May 21, 2026
May 20, 2026
Risk/Reward Ratio Explained: The Win Rate Each Ratio Requires
A 1:3 ratio does not make you right more often — it lets you be wrong three times out of four and still break even. Here is the inversion, a table of ratio against required win rate, and what costs do to both.
Camille Laurent · 6 min read
How Much Does a Space Heater Cost to Run?
Multiply the heater's kilowatts by hours used and your price per kWh — a 1.5 kW heater for 5 hours a day adds up fast at typical tariffs.
Marco Bianchi · 5 min read
The Total Cost of a Loan, Explained
Learn why a loan costs far more than the amount borrowed, how total interest builds over the term, and why a longer term means paying more.
Camille Laurent · 4 min read
May 19, 2026
Crypto Market Cap vs Trading Volume: What Each Number Can and Cannot Tell You
Market cap is price times circulating supply — an arithmetic product, not money invested. Volume is what actually changed hands. Here is what each measures, how their ratio exposes a thin market, and where fully diluted valuation fits.
Camille Laurent · 7 min read
How Moon Phases Work: Two Months, Eight Shapes, and No Shadow
The phase cycle takes 29.53 days but the orbit takes only 27.32, and the 2.21-day gap is the entire explanation. With the eight phases, their illumination, when each rises and sets, and how they flip south of the equator.
Lena Hoffmann · 7 min read
Meat Doneness Temperatures: A Safe Cooking Guide
The only reliable way to know meat is safe is internal temperature. Learn safe minimum internal temperatures for poultry, ground meat, pork, beef and fish, and how to check with a thermometer.
Marco Bianchi · 3 min read
VO2 Max Norms by Age: What Your Number Means
What VO2max measures, how it ranges by age and sex in ml/kg/min, and the training that raises it.
Aisha Karim · 3 min read
May 18, 2026
How to Solve Stoichiometry Problems: Grams to Moles to Ratio to Grams
Every problem in the chapter is the same four moves. The mole ratio is the hinge, and it is the step students lose — worked here end to end, limiting reactant and percent yield included.
Lena Hoffmann · 7 min read
How Much Fiber Per Day Do You Need?
Daily fiber targets of 25 to 38 grams by sex and age, why fiber matters for digestion and heart health, and the best food sources to hit your goal.
Sofia Nunes · 3 min read
May 15, 2026
How Staking Rewards Actually Work: Nominal Rate, Compounding, and What Eats It
An advertised 8 percent becomes 8.33 percent once daily rewards compound — and then 7.46 percent after a 10 percent validator commission, and less again after unbonding time. Here is each step, with the arithmetic laid out.
Camille Laurent · 6 min read
How to Calculate pH — And When the Weak-Acid Shortcut Stops Working
Four routes for four kinds of solution, each worked with real numbers. Including the part most pages leave out: the square-root formula for a weak acid is an approximation with a validity limit, and it fails quietly.
Lena Hoffmann · 7 min read