When you need to know how to calculate permutation, the shortest answer is: for selecting r items from n distinct items where order matters and no repeats, use P(n,r) = n! / (n-r)!. If repetition is allowed, it’s n^r. For…
How to Calculate Fractions: The Straight Answer Calculating a fraction means performing arithmetic on parts of a whole—whether you’re adding, subtracting, multiplying, dividing, or finding a fraction of a number. The fastest answer: to find a fraction of a quantity,…
The Core Difference: How to Calculate Markup vs Margin (And Why It Matters Now) If you run a business, knowing how to calculate markup vs margin is the difference between pricing for profit and quietly bleeding cash. Markup is the…
If you need to know how to calculate aspect ratio, here’s the straight answer: divide the width by the height, then simplify that fraction to its lowest integer terms using the greatest common divisor (GCD). The formula is AR =…
The Core CBM Formula Every Shipper Must Memorize If you’re asking “how do you calculate volume in CBM?”, the answer is straightforward: measure your item’s length, width, and height in meters, then multiply them together (CBM = L × W…
The Real Way to Convert Clothing Sizes (Not Just a Chart) If you want to know how to convert clothing sizes between the US, UK, EU, and Asian systems, stop screenshotting static charts. The only reliable method is to measure…
How to Calculate Step Calories Burned by Hand To calculate step calories burned manually, use the MET‑based equation: calories per step = (MET × 3.5 × weight_kg ÷ 200) ÷ steps per minute. For a 150‑lb (68 kg) person walking 3 mph…
How to Calculate Vegan Protein Needs Manually (With Bioavailability) Most vegans need about 1.0–1.2 grams of plant protein per kilogram of body weight daily, but that raw number is misleading because plant proteins have lower digestibility. To calculate your true…
Knowing how to calculate pregnancy weight gain starts with one number: your pre-pregnancy BMI. The manual method is weight (kg) ÷ height (m²), then map that BMI to the Institute of Medicine (IOM) ranges adopted by the CDC. For a…
To calculate your fertility window by hand, you need two numbers: your average menstrual cycle length (day 1 of bleeding to the day before next bleed) and your luteal phase length (days from ovulation to next period). Subtract the luteal…