Decimal
0.15 × 20 = 3
Fraction
— (no clean fraction)
Equation
(15 ÷ 100) × 20 = 3
How to calculate 15% of 20
Two steps — convert to a decimal, then multiply.
- 1
Convert the percentage to a decimal
15 ÷ 100 = 0.15
- 2
Multiply the original number by the decimal
0.15 × 20 = 3
Where 15% of 20 comes up in practice
A 15% tip on a $20 restaurant bill comes out to $3.00, bringing the total to $23.00.
How to read this number
- 15% is the long-running US baseline for adequate restaurant service. A $3.00 tip on a $20.00 bill brings the total to $23.00.
Mental math shortcut
10% + half of 10% (15% = 1.5 × 10%).
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.
- 3 is 15% of 20
- 3 out of 20 = 15%
- 15% off $20.00 = $17.00
Frequently asked
Common follow-up questions for 15% of 20.
Yes — multiplying by the decimal form (0.15) is exactly what "15% of 20" means. 20 × 0.15 = 3.
No — 15% of $20 is the discount amount itself ($3.00). 15% off $20 means the sale price is $17.00 (the original price minus the discount).
10% + half of 10% (15% = 1.5 × 10%). For 15% of 20 that gives 3 directly.
The number is 20. To work it out, divide 3 by 0.15: 3 ÷ 0.15 = 20.
Total = $23.00. The bill ($20) plus a 15% tip ($3.00) = $23.00.
Need a different calculation?
Use the full Percentage Calculator — five modes including reverse calculations, percentage change, and percentage difference.
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