Percentage Calculator: 5 Ways to Calculate Percentages Instantly
Percentages are everywhere — from store discounts and tip calculations to tax rates and investment returns. Yet mental percentage math trips up even the sharpest among us.
Our free percentage calculator handles all common percentage problems in one place.
5 Percentage Calculations Everyone Should Know
1. X% of Y — “What is 20% of 150?”
The most common use case. Calculate discounts, tax amounts, or proportions. Example: What’s 20% off a $150 item? Answer: $30 off ($120 final).
2. X Is What % of Y — “50 is what percent of 200?”
Great for calculating scores, ratios, or progress. Example: You scored 45 out of 60 on a test. That’s 75%.
3. Percentage Change — “From 100 to 120 is what % change?”
Track growth, price changes, or performance. Example: Revenue grew from $10K to $12.5K — that’s a 25% increase.
4. Percentage Increase — “Add 15% to 200”
Calculate prices after tax, markup, or tips. Example: A $200 item with 15% tax = $230.
5. Percentage Decrease — “Subtract 25% from 80”
Calculate sale prices or discounts. Example: 25% off $80 = $60.
Real-World Uses for a Percentage Calculator
| Scenario | Calculation Type |
|---|---|
| Shopping discount | X% decrease |
| Restaurant tip | X% increase |
| Exam score | X is what % of Y |
| Investment return | % change |
| Sales tax | X% of Y |
| Body fat percentage | X is what % of Y |
Why Use Our Percentage Calculator
- All 5 modes in one tool — no need for multiple calculators
- Instant results — see answers as you type
- Step-by-step — understand the math, not just the answer
- Free and private — no data collection, no ads tracking
Quick Mental Math Tricks
- 10% of any number — move the decimal one place left (10% of 250 = 25)
- 5% — take half of 10% (5% of 250 = 12.5)
- 15% — add 10% + 5% (15% of 250 = 25 + 12.5 = 37.5)
- 1% — move the decimal two places left (1% of 250 = 2.5)
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