Decimal
0.2 × 30 = 6
Fraction
⅕ of 30 = 6
Equation
(20 ÷ 100) × 30 = 6
How to calculate 20% of 30
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 × 30 = 6
Where 20% of 30 comes up in practice
A 20% tip on a $30 restaurant bill comes out to $6.00, bringing the total to $36.00.
How to read this number
- 20% is the modern US standard tip for good service — $6.00 on a $30.00 bill brings the total to $36.00.
Mental math shortcut
⅕ — divide by 5. Or take 10% and double it.
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.
- 6 is 20% of 30
- 6 out of 30 = 20%
- 20% off $30.00 = $24.00
Frequently asked
Common follow-up questions for 20% of 30.
Yes — multiplying by the decimal form (0.2) is exactly what "20% of 30" means. 30 × 0.2 = 6.
20% equals ⅕. So ⅕ of 30 = 6, which is the same answer reached the long way.
No — 20% of $30 is the discount amount itself ($6.00). 20% off $30 means the sale price is $24.00 (the original price minus the discount).
⅕ — divide by 5. Or take 10% and double it. For 20% of 30 that gives 6 directly.
The number is 30. To work it out, divide 6 by 0.2: 6 ÷ 0.2 = 30.
Total = $36.00. The bill ($30) plus a 20% tip ($6.00) = $36.00.
Need a different calculation?
Use the full Percentage Calculator — five modes including reverse calculations, percentage change, and percentage difference.
Open Percentage Calculator