Percentage change

What is percentage change?

Percentage change is the difference between a new value and an original value, expressed as a percentage of the original: ((new − old) / old) × 100. GCSE Maths uses it for percentage increase/decrease, reverse percentages (finding the original before a known change), and multiplier methods (×1.05 for a 5% rise). The multiplier method is fastest and least error-prone for higher-tier work.