Percentage Calculator
Calculate Percentage of Number, Increase, Decrease, Difference & More
Published: November 15, 2025 | Updated: November 15, 2025
Published by: RevisionTown Team
Percentage calculations are essential in everyday life—from calculating grades, discounts, and tips to analyzing financial data, tracking progress, and making informed decisions. This comprehensive calculator handles all percentage calculations including finding percentages of numbers, percentage increases and decreases, percentage differences, reverse percentages, and specialized conversions like GPA to percentage.
Whether you're a student calculating exam percentages, a professional analyzing business metrics, or a shopper comparing prices, this tool provides instant, accurate results with detailed formulas and step-by-step explanations.
Percentage Calculator
Percentage Formulas
1. Basic Percentage Formula
Calculate what percentage one number is of another:
Example: 15 out of 60 = (15 ÷ 60) × 100 = 25%
2. Percentage of a Number
Find X% of Y:
Example: 20% of 150 = (20 ÷ 100) × 150 = 30
3. Percentage Increase
Calculate percentage increase from old to new value:
Example: From 50 to 65 = [(65 - 50) ÷ 50] × 100 = 30% increase
4. Percentage Decrease
Calculate percentage decrease from old to new value:
Example: From 80 to 60 = [(80 - 60) ÷ 80] × 100 = 25% decrease
5. Percentage Difference
Compare two values (no reference point):
Example: Between 40 and 60 = [|40-60| ÷ 50] × 100 = 40% difference
Percentage Calculation Examples
Calculate Grade Percentage
Problem: Scored 420 out of 500
Solution: (420 ÷ 500) × 100
= 84%
Calculate Tip Amount
Problem: 15% tip on $80 bill
Solution: (15 ÷ 100) × 80
= $12 tip
Salary Increase
Problem: Salary rose from $50k to $57.5k
Solution: [(57.5-50) ÷ 50] × 100
= 15% raise
Weight Loss Percentage
Problem: Lost weight from 200 lbs to 180 lbs
Solution: [(200-180) ÷ 200] × 100
= 10% loss
Commission Calculation
Problem: 8% commission on $5,000 sales
Solution: (8 ÷ 100) × 5000
= $400
GPA to Percentage
Problem: 3.6 GPA on 4.0 scale
Solution: (3.6 ÷ 4.0) × 100
= 90%
Frequently Asked Questions
How do you calculate percentage?
To calculate a percentage: Divide the part by the whole and multiply by 100. Formula: Percentage = (Part / Whole) × 100. Example: 25 out of 100 = (25/100) × 100 = 25%.
How to calculate percentage of a number?
To find what percentage one number is of another: (Number / Total) × 100 = Percentage. Example: What percent is 15 of 60? (15/60) × 100 = 25%. Or to find X% of Y: (X/100) × Y. Example: 20% of 50 = (20/100) × 50 = 10.
How to calculate percentage increase?
Formula: [(New Value - Old Value) / Old Value] × 100. Example: Price increased from $50 to $65. Increase = [(65-50)/50] × 100 = 30% increase.
How to calculate percentage decrease?
Formula: [(Old Value - New Value) / Old Value] × 100. Example: Price decreased from $80 to $60. Decrease = [(80-60)/80] × 100 = 25% decrease.
What is percentage difference?
Percentage difference compares two values relative to their average. Formula: [|Value1 - Value2| / ((Value1 + Value2)/2)] × 100. It's used when neither value is a clear reference point.
How to convert GPA to percentage?
For 4.0 scale: Percentage = (GPA / 4.0) × 100. For 10.0 scale: Percentage = GPA × 9.5. Example: 3.5 GPA on 4.0 scale = (3.5/4.0) × 100 = 87.5%.
Master Percentage Calculations
Understanding percentage calculations is a fundamental skill that applies to academics, finance, business, health, and everyday decision-making. This comprehensive calculator provides 10+ calculation modes to handle any percentage-related problem—from simple calculations like finding 20% of a number to complex scenarios like percentage difference and GPA conversions.
Whether you're calculating exam percentages, analyzing salary increases, determining profit margins, tracking weight loss progress, or converting academic scores, this tool delivers instant, accurate results with detailed formulas and step-by-step explanations. Use the various calculation modes to solve your specific percentage problems and understand the mathematical concepts behind each calculation.
