Quick Answer
To convert percent into decimal, divide by 100.
This simple rule works for every percentage, from tiny decimals like 0.05% to large numbers like 500%.
Why This Works
"Percent" means "per 100" in Latin. So when you see 75%, you're really seeing 75 per 100, or 75/100. Converting to decimal means expressing this as a standard number.
75/100 = 0.75
Two Ways to Convert
Method 1: Division
Divide the percentage by 100:
- 30% = 30 ÷ 100 = 0.30
- 7% = 7 ÷ 100 = 0.07
- 125% = 125 ÷ 100 = 1.25
Method 2: Move the Decimal
Count two places to the left:
- 45% → 4.5 → 0.45
- 8% → 0.8 → 0.08
- 200% → 20.0 → 2.00
Method 1: 15 ÷ 100 = 0.15
Method 2: 15 → 1.5 → 0.15
Conversion Reference Table
| Percentage | Decimal | Fraction | Use Case |
|---|---|---|---|
| 1% | 0.01 | 1/100 | Small fees |
| 5% | 0.05 | 1/20 | Sales tax |
| 10% | 0.10 | 1/10 | Tips, discounts |
| 25% | 0.25 | 1/4 | Quarter portions |
| 50% | 0.50 | 1/2 | Half |
| 100% | 1.00 | 1/1 | Whole amount |
Real-World Applications
Shopping: A $60 item is 20% off. How much savings?
Convert 20% to 0.20
$60 × 0.20 = $12 savings
Banking: You earn 3% APY on $2,000. How much interest?
Convert 3% to 0.03
$2,000 × 0.03 = $60 interest
Taxes: Sales tax is 7.5% on a $40 purchase.
Convert 7.5% to 0.075
$40 × 0.075 = $3.00 tax
Special Cases
Percentages Over 100%
These convert to decimals greater than 1:
- 150% = 1.50
- 300% = 3.00
Decimal Percentages
The rule still applies:
- 5.5% = 0.055
- 0.25% = 0.0025
Common Mistakes
- Wrong direction: Moving decimal right instead of left
- Missing zeros: Writing 0.5 for 5% instead of 0.05
- Keeping the %: The symbol should disappear after conversion
Checking Your Answer
Multiply your decimal by 100 to verify:
0.25 × 100 = 25% ✓
Summary
Converting percent to decimal is a fundamental math skill. Remember: divide by 100 or move the decimal two places left. Practice with different percentages until it becomes automatic.
Use our Percentage Calculator to verify your conversions.