How-To Guides: Step-by-Step Tutorials

Our comprehensive guides help you master calculations with easy-to-follow steps and examples.

How to Calculate Percentage

  1. Identify the part and the whole values.
  2. Divide the part by the whole.
  3. Multiply the result by 100 to get the percentage.
  4. Example: To find what percentage 50 is of 200: (50 / 200) × 100 = 25%.

Common Use: Discounts, grades, statistics.

How to Calculate Growth Rate

  1. Subtract initial value from final value.
  2. Divide the difference by the initial value.
  3. Multiply by 100 for percentage.
  4. Example: From 100 to 150: ((150 - 100) / 100) × 100 = 50% growth.

Common Use: Business metrics, population changes.

How to Calculate Average

  1. Sum all numbers in the set.
  2. Divide by the count of numbers.
  3. Example: Average of 10, 20, 30: (10 + 20 + 30) / 3 = 20.

Common Use: Statistics, scores, data analysis.

How to Calculate Square Root

  1. Identify the number.
  2. Use the square root function (√).
  3. Example: √25 = 5, since 5 × 5 = 25.

Common Use: Geometry, physics.

How to Calculate Compound Interest

  1. Use formula: A = P(1 + r/n)^(nt)
  2. P = principal, r = rate, n = compounds per year, t = time.
  3. Example: $1000 at 5% annually for 3 years: 1000(1 + 0.05/1)^(1*3) = $1157.63.

Common Use: Savings, investments.

How to Calculate BMI

  1. Divide weight (kg) by height squared (m²).
  2. Example: 70kg / (1.75m)² = 22.86.
  3. Interpret: Under 18.5 underweight, 18.5-24.9 normal.

Common Use: Health assessment.

How to Calculate Loan Payment

  1. Use formula: PMT = P(r(1+r)^n) / ((1+r)^n - 1)
  2. Example: $10000 at 5% for 5 years monthly.

Common Use: Mortgages, car loans.

How to Calculate Tip

  1. Multiply bill by tip percentage/100.
  2. Example: $50 at 20%: $10 tip.

Common Use: Restaurants, services.