Percentage Calculator — Find Percent, Increase, Decrease & MoreX% of Y · % Change · % Difference · Part/Whole · Reverse % · Increase & Decrease
Use this free Percentage Calculator to instantly solve every type of percentage calculation across six core calculation modes: What is X% of Y? (e.g. 15% of 200 = 30) · X is what % of Y? (e.g. 30 is what % of 200?) · Percentage increase (% change from old to new value) · Percentage decrease (% reduction from original value) · Reverse percentage — find the original value before % change · Percentage difference between two values — using the standard percentage formulas: % = (Part / Whole) × 100 and % Change = [(New − Old) / Old] × 100 — delivering instant, accurate results for any numbers.
This online percent calculator is trusted for every academic and professional percentage calculation need: exam score and grade percentage calculation (marks obtained / total marks × 100), discount and sale price percentage calculation for shopping, GST, VAT, and sales tax percentage calculation, profit margin and markup percentage for business pricing, percentage increase in salary, revenue, or investment returns, body weight loss or gain percentage for health tracking, CGPA to percentage conversion (CGPA × 9.5 for CBSE), and data analysis — percentage share, growth rate, and proportion calculations. Trusted by students, teachers, shoppers, accountants, analysts, business owners, and financial planners worldwide for fast, accurate percentage math — no manual calculation required.
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Percentage Calculator — Five Percentage Problems, One Tool
Percentage calculations seem simple but there are five distinct problems that get conflated. (1) What is X% of Y? (2) X is what percent of Y? (3) What is the percent change from X to Y? (4) Y is X% more/less than what original value? (5) X increased/decreased by Y% gives what result? Each requires a different formula, and using the wrong one produces wildly incorrect answers. A 25% increase followed by a 25% decrease does not return to the original — it ends at 93.75% of the original because the 25% decrease is applied to the larger number. The percentage calculator explicitly identifies which problem type is being solved.
Percent change and percentage point change are entirely different and the confusion between them distorts political and economic reporting constantly. If a mortgage rate rises from 4% to 6%, the rate increased by 2 percentage points but increased by 50% in relative terms. Reporting "interest rates up 50%" and reporting "interest rates up 2 percentage points" describe identical events from different frames. The percentage calculator computes both and labels each clearly.
Compounding percentage changes requires multiplication, not addition. A stock that gains 10% one year and loses 10% the next year does not return to its starting price — it ends at 99% of the original because 100 × 1.10 × 0.90 = 99. A stock that gains 50% then loses 33.3% returns to exactly the starting price because 1.50 × 0.667 = 1.00. Understanding this asymmetry is essential for evaluating investment performance — the calculator shows multi-period compound percentage changes correctly.