Percentage Calculator
Free online percentage calculator — X% of a number, what percent X is of Y, and percent change (increase or decrease). Same arithmetic in the UK, NZ, and Excel.
This percentage calculator handles the three everyday jobs: a percent of a number, a number as a percent of another (marks, attendance, win rate), and percentage increase or decrease (hike, growth, discount, weight loss). It is not a GPA/SGPA converter, body-fat %, love calculator, or tax engine — those are linked where they belong.
Percentage calculator formula
part = whole × percent ÷ 100. percent = part ÷ whole × 100. change = (new − old) ÷ old × 100.
Percentage calculator reverse: if you know the part and the percent, whole = part ÷ (percent ÷ 100). Added percentage (increase a price 10%): new = old × 1.10. Markup vs margin are different — use the markup calculator for selling price from cost.
How to use this percentage calculator
- Enter value X and value Y.
- Read “X% of Y” when X is the percent (25 and 200 → 50).
- Read “X is what % of Y” for marks, attendance, or win–loss (45 of 60 → 75%).
- Read percent change from Y to X for increase, decrease, hike, or growth (80 to 100 → 25% up). In Excel: = (new-old)/old*100.
About this calculator
Percentage on a calculator formula: part = whole × percent ÷ 100; percent = part ÷ whole × 100; change = (new − old) ÷ old × 100. Do percentage calculator: enter X and Y, then read all three lines so you do not mix “25% of 200” with “25 is what % of 200.” How to find a percentage on a calculator: divide part by whole, multiply by 100. How to work out a percentage: same steps; Excel is =A1/B1*100 or =A1*B1/100 depending on which question you mean.
Marks, exams, SSLC, 10th, and student totals use “X is what % of Y” (obtained ÷ maximum × 100). A reverse or “is of” percentage calculator is that second line. Percentage calculator difference / growth / hike / raise / pay increase / price increase / inflation of two prices is percent change from Y (old) to X (new). Reduce by percentage: new = old × (1 − percent ÷ 100), or use the discount calculator for a sale price.
GPA to percentage, SGPA to percentage, CGPA, and IGNOU scales are university rules (often SGPA × 10 minus a constant), not this generic tool — use the GPA calculator. Fraction into percentage: (numerator ÷ denominator) × 100, or the fraction-to-decimal tool then × 100. Decimal to percentage: × 100. Body fat (Army, Navy, US Navy, women), BMI to fat %, blood alcohol, love/name percentage, slugging, VA disability, slope, probability, and SIP/loan/tax engines are different quantities — links below, not stuffed into this form.
Examples
Percent of a number
X = 25, Y = 200 → 25% of 200 = 50.
Marks to percentage
X = 72, Y = 80 → 72 is 90% of 80.
Percentage increase (hike or price)
Old Y = 80, new X = 100 → change = 25% increase. From 100 down to 80 is a 20% decrease.
Increase, decrease, discount, and difference
Increase of percentage, growth, raise, and pay increase all use percent change. Difference in percentage between two amounts is the same line (sign shows up or down). Percentage calculator off / discount: sale = original × (1 − off ÷ 100), or open the discount percentage calculator for a price tag. Profit, gain, and loss percent: (selling − cost) ÷ cost × 100 — related markup/margin tools refine that for shops.
School, Excel, and what we do not calculate
UK and NZ percentage calculators use this same arithmetic. Average of several percents is not a single X/Y pair — use the average calculator if you must combine rates carefully. Time percentage (hours of a day) is still part ÷ whole; a dedicated time tool helps with hours and minutes.
Not included: blood alcohol %, alcohol by volume as a lab assay, name/love percentage, slugging percentage, VA disability %, slope %, probability models, Calculator Soup clones, or an “app for percentage calculator” beyond this free web page. Attendance % is scored ÷ held × 100 on the middle result.
FAQ
Percentage calculator?+
A percentage calculator turns two numbers into a percent of a whole, a part as a percent, or a percent change. This online tool shows all three so homework, discounts, and stats use the right line.
Do percentage calculator?+
Enter X and Y. If you want 20% of 150, put 20 and 150 and use “X% of Y.” If you want “30 is what percent of 50,” put 30 and 50 and use the middle result.
How do I find a percentage on a calculator?+
Divide the part by the whole, then multiply by 100. Example: 18 ÷ 60 × 100 = 30%. On this page that is “X is what % of Y.” Percent of a number is the other way: 30% of 60 is 0.30 × 60 = 18.
What percentage calculator?+
This one: percent of a number, number as a percent, and increase/decrease. It is not Calculator Soup, not a love calculator, and not a UK tax or federal income-tax percentage calculator — those need tax bands.
How do I calculate percentage increase?+
Percent change = (new − old) ÷ old × 100. Put the new value in X and the old in Y. A 10% hike on 40,000 is 44,000: (44000 − 40000) ÷ 40000 × 100 = 10%. Decrease uses the same formula (the result is negative).
How do I get marks to percentage?+
Marks percentage = scored ÷ maximum × 100. Example: 72 of 80 is 90%. SSLC / 10th / exam totals work the same. GPA or SGPA to percentage depends on your board — not a single formula here.
What is the Excel percentage formula?+
Percent of: =percent*whole/100. What percent: =part/whole. Percent change: =(new-old)/old. Format the cell as Percentage, or multiply by 100 yourself.
Is this a body-fat or GPA percentage calculator?+
No. Army/Navy fat %, BMI to fat %, and “good body fat percentage” belong on the body-fat and BMI tools. GPA/CGPA/SGPA converters belong on the GPA calculator. Loan, SIP, interest, and tax percentages need those finance calculators.