The answer is 30. Below: three ways to calculate it, a mental shortcut, and the real-world contexts where this percentage shows up.
30% of 100 is 30.
Some US states and many international jurisdictions have tax rates near 30% on certain categories.
Divide the percent by 100 to convert it: 30 ÷ 100 = 0.3.
Multiply: 100 × 0.3 = 30.
30% means 30/100. So 30% of 100 is (30 × 100) ÷ 100.
Compute: 30 × 100 = 3000, then divide: 3000 ÷ 100 = 30.
No single elegant mental shortcut for 30% — but you can always split: 30% = (some 10%) + (some 5%) + (some 1%). Try 3×(10% of 100) plus 0×(1% of 100).
Sales tax is a percentage added to a purchase. To find the total, calculate the tax first, then add it to the price.
On a $100 purchase with 30% tax, the tax amount is $30 and you pay $130 total.
If you only needed to look up this one number, here are some related ones using the same base of 100:
| Calculation | Answer |
|---|---|
| 5% of 100 | 5 |
| 6% of 100 | 6 |
| 7% of 100 | 7 |
| 8% of 100 | 8 |
| 10% of 100 | 10 |
| Calculation | Answer |
|---|---|
| 30% of 5 | 1.5 |
| 30% of 6 | 1.8 |
| 30% of 7 | 2.1 |
| 30% of 8 | 2.4 |
| 30% of 10 | 3 |
For any percentage of any number, use our percentage of a number calculator.
Multiply 100 by 0.3 (the decimal form of 30%). Or equivalently, multiply by 30/100. The result is 30.
Divide 30 by 100 and multiply by 100. That is exactly 30% — confirming the original calculation.
The tax is 30, so the total is 130.