Radius of Gyration Calculator

Radius of Gyration Calculator: engineering calculator for radius of gyration. Formula derivation, tolerances, and design tips.

Percentage formulas

X is what % of Y: (X ÷ Y) × 100

X% of Y: (X ÷ 100) × Y

% change from A to B: ((B − A) ÷ A) × 100

Original value before X% added: Final ÷ (1 + X/100)

Original value before X% removed: Final ÷ (1 − X/100)

Worked examples: 45 is what % of 180? (45 ÷ 180) × 100 = 25%. 15% of 240? 0.15 × 240 = 36. Price rose from 80 to 96 — % increase: ((96−80) ÷ 80) × 100 = 20%. Price was 120 after 20% tax added — original pre-tax: 120 ÷ 1.20 = 100.