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Percentage Calculator – Calculate Percentages

Free percentage calculator for all your needs. Calculate percentages, percentage change, increase/decrease, and more. Easy to use with step-by-step formulas.

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Disclaimer

This calculator provides estimates for informational purposes only. Results may vary based on individual circumstances. Consult a qualified financial professional or tax advisor for personalized advice. Tax rates and brackets are based on 2026 data and are subject to change.

The Three Percentage Calculations You Use Every Day

Nearly every percentage question falls into one of three types: (1) What is X% of Y? (e.g., what is 15% of $85?). (2) X is what percent of Y? (e.g., 45 correct out of 60 questions = what percent?). (3) What is the percentage change from X to Y? (e.g., price went from $80 to $96 — what percent increase?). Mastering these three formulas covers discounts, exam scores, pay raises, investment returns, and any other percentage calculation you encounter.

Three Percentage Formulas with Examples

(1) X% of Y: multiply Y by X/100. What is 15% of $85? 85 × 0.15 = $12.75. (2) X is what percent of Y: (X/Y) × 100. 45 out of 60 = (45/60) × 100 = 75%. (3) Percentage change: ((New − Old) / Old) × 100. From $80 to $96 = ((96−80)/80) × 100 = 20% increase. Select the calculation type in the calculator above, enter your numbers, and see the result with the formula shown.

Frequently Asked Questions

(Part / Whole) × 100 = Percentage. Example: 36 out of 90 = (36/90) × 100 = 40%. This is the most common percentage calculation — exam scores, survey results, completion rates.
((New Value − Old Value) / Old Value) × 100. From $80 to $100: ((100−80)/80) × 100 = 25% increase. From $100 to $80: ((80−100)/100) × 100 = −20% (a 20% decrease).
Original Price = Sale Price / (1 − Discount Rate). Item costs $68 after 15% discount: $68 / (1 − 0.15) = $68 / 0.85 = $80.00 original price. Verify: $80 × 0.15 = $12 discount. $80 − $12 = $68. Correct.
Percentage points are the arithmetic difference between two percentages. Percent change is the relative change. If approval rating rises from 40% to 50%: it rose 10 percentage points, but increased by 25% in relative terms (10/40 × 100 = 25%). These are very different numbers — a key distinction in political reporting.
For 20% tip: move decimal left one place to find 10%, double it. On $65: 10% = $6.50, double = $13.00 for 20% tip. For 15%: find 10% ($6.50), halve it ($3.25), add together = $9.75. For 18%: use the calculator — it is not clean mental math.