How Many Deck Boards Do I Need? Coverage and Gaps
Work out deck boards from the deck area, each board's covered width including the gap, and a waste allowance for cuts and the picture-frame border.
Marco Bianchi · 3 min read
Guides & tutorials
Practical guides, how-tos and comparisons to get the most out of our free online tools.
January 27, 2026
January 26, 2026
What Is Inventory Turnover? (And What's a Healthy Ratio)
Inventory turnover shows how many times you sell through your stock in a year. Learn the formula — COGS divided by average inventory — and what a healthy ratio looks like.
Daniel Okonkwo · 4 min read
How to Calculate an LED Series Resistor
Size the series resistor for any LED with one formula: R = (Vs − Vf) / I. Follow the steps, see a worked 5 V example, and pick the right resistor.
Lena Hoffmann · 5 min read
How Far Apart to Plant? Spacing and Plants per Area
Turn a plant-spacing figure into how many plants you need for a bed or row — including the difference between square and triangular layouts.
Marco Bianchi · 3 min read
How Credit Card Interest Works: APR and the Minimum Trap
Learn how card APR becomes a daily periodic rate, why interest compounds daily, and how minimum payments can stretch a balance out for years.
Camille Laurent · 2 min read
January 23, 2026
How to Estimate Video File Size (Bitrate x Duration)
Estimate any video's file size before you export. Learn the bitrate-times-duration formula, why you divide by 8, and how resolution and frame rate change the result.
Daniel Okonkwo · 5 min read
How Much Meat Per Person (Portions by Cut and Occasion)
Plan portions with confidence: boneless meat, bone-in cuts and whole birds each need different amounts per guest.
Marco Bianchi · 4 min read
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
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