Decimal
0.2 × 100 = 20
Fraction
⅕ of 100 = 20
Equation
(20 ÷ 100) × 100 = 20
How to calculate 20% of 100
Two steps — convert to a decimal, then multiply.
- 1
Convert the percentage to a decimal
20 ÷ 100 = 0.2
- 2
Multiply the original number by the decimal
0.2 × 100 = 20
Where 20% of 100 comes up in practice
A 20% tip on a $100 restaurant bill comes out to $20.00, bringing the total to $120.00.
How to read this number
- 20% is the modern US standard tip for good service — $20.00 on a $100.00 bill brings the total to $120.00.
Mental math shortcut
⅕ — divide by 5. Or take 10% and double it.
Other percentages of 100
Common percentages applied to the same amount. Click any row to see its full breakdown.
| Calculation | Result |
|---|---|
| 10% of 100 | 10 |
| 12% of 100 | 12 |
| 15% of 100 | 15 |
| 18% of 100 | 18 |
| 20% of 100You are here | 20 |
| 22% of 100 | 22 |
| 25% of 100 | 25 |
20% of other amounts
Same percentage applied to nearby amounts. Useful when you want to compare values around 100.
| Calculation | Result |
|---|---|
| 20% of 50 | 10 |
| 20% of 60 | 12 |
| 20% of 75 | 15 |
| 20% of 80 | 16 |
| 20% of 100You are here | 20 |
| 20% of 120 | 24 |
| 20% of 150 | 30 |
The same calculation, expressed three ways
Knowing one of these gives you the other two — handy when a problem is phrased differently to what you typed.
- 20 is 20% of 100
- 20 out of 100 = 20%
- 20% off $100.00 = $80.00
Frequently asked
Common follow-up questions for 20% of 100.
Yes — multiplying by the decimal form (0.2) is exactly what "20% of 100" means. 100 × 0.2 = 20.
20% equals ⅕. So ⅕ of 100 = 20, which is the same answer reached the long way.
No — 20% of $100 is the discount amount itself ($20.00). 20% off $100 means the sale price is $80.00 (the original price minus the discount).
⅕ — divide by 5. Or take 10% and double it. For 20% of 100 that gives 20 directly.
The number is 100. To work it out, divide 20 by 0.2: 20 ÷ 0.2 = 100.
Total = $120.00. The bill ($100) plus a 20% tip ($20.00) = $120.00.
Need a different calculation?
Use the full Percentage Calculator — five modes including reverse calculations, percentage change, and percentage difference.
Open Percentage Calculator