- How to Calculate a Percentage?
- How Are Percentages Used in Everyday Life?
- How to Calculate a Percentage Increase?
- How to Calculate a Percentage Decrease?
- How to Calculate a Reverse Percentage?
- How to Convert a Percentage to a Grade?
- How to Calculate Body Fat Percentage?
- How to Calculate Tax Percentage in Australia?
- How to Calculate CCS (Child Care Subsidy) Percentage?
- How to Calculate Child Support Percentage in Australia?
- How to Calculate AFL Percentage?
- How to Calculate Win Percentage?
- How to Make a Percentage Calculator in Excel?
Percentages are a quick and easy way to compare numbers, track changes, and understand proportions. Whether you're calculating discounts while shopping, checking your exam scores, or comparing mortgage rates, percentages are everywhere in daily life.
A percentage expresses a number as a fraction of 100. It is widely used in finance, education, health, fitness, and sports to analyse data and make informed decisions.
How to Calculate a Percentage?
To calculate a percentage, use this simple formula:
Percentage = (Part ÷ Total) × 100
For example
You have 10 Tim Tams, and you eat 4. What percentage have you eaten?
- Divide the part (4 Tim Tams) by the total (10 Tim Tams): 4 ÷ 10 = 0.40
- Multiply by 100: 0.40 × 100 = 40%
So, you ate 40% of the Tim Tams
If you need to quickly calculate percentages, try our online percentage calculator!
How Are Percentages Used in Everyday Life?
Percentages help us compare values, track changes, and make better financial decisions. Here are some real-world examples:
Shopping: Discounts & Sales
You’re shopping at Myer during a sale, and a jacket originally priced at $200 is 30% off.
To calculate the discount:
200 × 0.30 = 60
You save $60, and the final price is:
200 - 60 = $140
Retail stores use percentage discounts to attract customers and increase sales.
Finance: Mortgage & Savings Rates
Percentages are essential in banking and investing, particularly for mortgage rates and savings interest.
If your bank offers 4% interest on a $10,000 savings account, your yearly earnings are:
10,000 × 0.04 = $400
The higher the percentage, the more you earn on savings!
Health & Nutrition: Food Labels
Ever read a food label and seen "8% sugar" on a juice bottle? That means in 100mL of juice, 8mL is sugar.
If a bottle contains 500mL:
500 × 0.08 = 40mL of sugar
Understanding percentages in nutrition helps you make healthier choices.
How to Calculate a Percentage Increase?
A percentage increase shows how much something has grown compared to its original value.
Formula:
Percentage Increase = ((New Value − Old Value) ÷ Old Value) × 100
increase percentage calculator
Your electricity bill was $150 last month, but this month it’s $180.
- Find the difference: 180 - 150 = 30
- Divide by the original value: 30 ÷ 150 = 0.20
- Multiply by 100: 0.20 × 100 = 20%
Your electricity bill increased by 20%. Use our increase percentage calculator to make quick calculations!
How to Calculate a Percentage Decrease?
A percentage decrease tells you how much something has reduced from its original value.
Formula:
Percentage Decrease = ((Old Value − New Value) ÷ Old Value) × 100
For example
A mobile phone originally cost $1,200, but now it's on sale for $900.
- Find the difference: 1,200 - 900 = 300
- Divide by the original price: 300 ÷ 1,200 = 0.25
- Multiply by 100: 0.25 × 100 = 25%
The phone is 25% cheaper. Need a fast answer? Use our online percentage calculator.
How to Calculate a Reverse Percentage?
A reverse percentage helps you find the original price before a discount or increase.
Good to know
You bought a laptop for $1,350 after a 10% discount, but you want to know the original price.
Since $1,350 represents 90% of the original price:
1,350 ÷ 0.90 = 1,500
So, the original price was $1,500 before the discount.
How to Convert a Percentage to a Grade?
In Australia, university and high school grades are sometimes converted to percentages.
Australian Grade Conversion Table
- 85-100% → High Distinction (HD)
- 75-84% → Distinction (D)
- 65-74% → Credit (C)
- 50-64% → Pass (P)
- 0-49% → Fail (F)
Grade percentage calculator
If you scored 82% in a university subject, this is a Distinction (D).
Australian universities may convert grades to GPA (Grade Point Average) for international applications.
Australian GPA Conversion Table:
- 85%+ → 7.0 GPA (High Distinction)
- 75-84% → 6.0 GPA (Distinction)
- 65-74% → 5.0 GPA (Credit)
- 50-64% → 4.0 GPA (Pass)
- Below 50% → 0.0 GPA (Fail)
GPA percentage calculator
If your university grade is 70%, it falls into the Credit (C) range, which is approximately a 5.0 GPA.
How to Calculate Body Fat Percentage?
Tracking body fat percentage is crucial for understanding your health and fitness levels. Unlike BMI (Body Mass Index), which only considers weight and height, body fat percentage measures how much of your body weight is fat versus muscle, bone, and water.
Common Methods to Calculate Body Fat Percentage
- Skinfold Calipers – Measures fat thickness at key body areas.
- Bioelectrical Impedance (Smart Scales & Gym Machines) – Uses electrical signals to estimate fat.
- DEXA Scan (Dual-Energy X-ray Absorptiometry) – The most accurate but costly method.
Basic Formula for Estimation (US Navy Method):
For men:
Body Fat % = 86.01 × log(Waist - Neck) - 70.041 × log(Height) + 36.76
For women:
Body Fat % = 163.205 × log(Waist + Hip - Neck) - 97.684 × log(Height) - 78.387
Body fat percentage calculator
- Height: 175cm
- Waist: 85cm
- Neck: 40cm
Using the formula:
Body Fat % ≈ 20%
How to Calculate Tax Percentage in Australia?
Taxes are an essential part of life in Australia, whether you're calculating income tax, GST, or payroll tax. In Australia, income tax is progressive, meaning the more you earn, the higher percentage you pay.
| Taxable Income ($) | Tax Rate |
|---|---|
| 0 - 18,200 | 0% (Tax-Free Threshold) |
| 18,201 - 45,000 | 19% |
| 45,001 - 120,000 | 32.5% |
| 120,001 - 180,000 | 37% |
| 180,001+ | 45% |
Tax percentage calculator!
You earn $80,000 per year.
- First $18,200 = $0 tax
- Next $26,800 (at 19%) = $5,092
- Remaining $35,000 (at 32.5%) = $11,375
Total Tax Payable = $16,467
How to Calculate CCS (Child Care Subsidy) Percentage?
If you’re a parent in Australia, the Child Care Subsidy (CCS) helps reduce the cost of child care.
Formula:
CCS % = (Household Income & Activity Level) → Subsidy Percentage
| Household Income ($) | CCS Percentage |
|---|---|
| 0 - 80,000 | 90% |
| 80,001 - 180,000 | 90% - 50% (sliding scale) |
| 180,001 - 530,000 | 50% - 0% (sliding scale) |
CSS Percentage Calculator
A family earns $120,000 per year.
- Their CCS percentage is 74%.
- If child care costs $100 per day, they pay only $26 per day after the subsidy.
How to Calculate Child Support Percentage in Australia?
Child support payments in Australia are based on income, number of children, and custody arrangements.
Formula:
Child Support = (Parent’s Income Contribution × Percentage of Care) - Costs of Children
For example
- Parent A earns $90,000
- Parent B earns $60,000
- Parent A has 70% custody
The formula considers income shares and care percentage, with payments adjusted based on the Department of Human Services (DHS) guidelines.
How to Calculate AFL Percentage?
In the AFL (Australian Football League), a team’s percentage helps rank teams with the same number of wins. It measures how effectively a team scores compared to the points conceded.
Formula:
AFL Percentage = (Points For ÷ Points Against) × 100
AFL Percentage Calculator
An AFL team has:
- Scored 2,000 points in a season
- Conceded 1,600 points
AFL Percentage = (2000 ÷ 1600) × 100 = 125.0%
A team with a higher percentage ranks higher when tied on wins.
How to Calculate Win Percentage?
Win percentage is useful for sports, gaming, and business success tracking.
Formula:
Win Percentage = (Wins ÷ Total Games) × 100
Win Percentage Calculator
An NRL team plays 20 games, winning 15.
Win Percentage = (15 ÷ 20) × 100 = 75%
How to Make a Percentage Calculator in Excel?
Microsoft Excel can automatically calculate percentages for you.
Step-by-Step Guide:
- Open Excel and enter your data in two columns (e.g., "Part" and "Total").
- In the next column, enter this formula: =(A2 ÷ B2) × 100
- Press Enter, and Excel will calculate the percentage.
- Drag the formula down to apply it to multiple rows.
- Format the column as Percentage (%) for better readability.
This method works for sales targets, grades, or financial data.
Percentages are essential in everyday life, from tracking finances and childcare costs to following AFL stats. Whether you’re estimating tax, win rates, or body fat, knowing how to calculate percentages helps make informed decisions.
For quick calculations, use our free online percentage calculator.
