How Long Does It Take to Walk a Given Distance?
Walking time is distance divided by speed. Learn the average walking speed of about 3 mph and how to estimate the time for any distance.
Aisha Karim · 3 min read
Guides & tutorials
Practical guides, how-tos and comparisons to get the most out of our free online tools.
January 23, 2026
What Is Lean Body Mass? LBM vs Fat Mass
Lean body mass is everything in your body that isn't fat. Learn how the Boer formula estimates it and why it matters for health and training.
Sofia Nunes · 3 min read
January 22, 2026
Significant Figures Explained: Counting, Rounding, and Why They Matter
Learn what counts as a significant figure, the rules for leading, trailing, and captive zeros, and how sig figs keep your calculated answers honest.
Lena Hoffmann · 4 min read
How Much Fencing Do I Need? Perimeter, Posts, Panels
Measure your run, then work out posts, panels, and rails from the perimeter and a standard post spacing so nothing is short on install day.
Marco Bianchi · 3 min read
January 21, 2026
Gear Inches, Development, and Why Cyclists Argue About Ratios
50/11 means nothing until you attach a wheel. Gear inches and metres of development, derived and converted, a full table for a real 12-speed drivetrain, and why the gear step between two sprockets decides whether you can hold a cadence.
Aisha Karim · 13 min read
How Long Does It Take to Charge an EV?
Charging time is battery energy needed divided by charger power. See how home AC and public DC compare, and why fast charging slows past 80%.
Marco Bianchi · 3 min read
What Size Solar Battery Do I Need? Sizing by Daily Use
Size a solar battery from your daily energy use, the days of autonomy you want, and the battery's usable depth of discharge.
Marco Bianchi · 3 min read
How Loan Payments Work: Amortization and Interest Explained
See how a fixed loan payment splits between principal and interest, how amortization shifts over time, and the formula behind the monthly number.
Camille Laurent · 2 min read
January 20, 2026
Expected Goals: What xG Actually Measures
xG is the fitted probability that a shot with a given set of features becomes a goal — a model output, not an observation. A worked match, the binomial arithmetic that says one game is far too few shots, and the limits nobody quotes.
Aisha Karim · 13 min read
What Is Horsepower? Mechanical hp, Metric PS, and kW
Horsepower measures the rate of doing work. Learn where the unit came from, how mechanical hp differs from metric PS/CV, and how both relate to kilowatts.
Lena Hoffmann · 4 min read
January 19, 2026
Climbing Grade Conversions Are Not Conversions
French, YDS, UIAA, V-scale and Font are ordinal scales with no underlying unit. A conversion table is a negotiated alignment between climbing communities — and published tables disagree by half a grade at the top and by four letter-grades at the bottom of the boulder scales.
Aisha Karim · 15 min read
How Long to Thaw a Turkey (Safely, Every Time)
Fridge thawing needs about 24 hours per 4 to 5 lb; the cold-water method is faster. Follow food-safety rules to avoid bacteria.
Marco Bianchi · 4 min read