Percentage Calculator
Calculate any percentage instantly, from tips and discounts to tax, grade scores, salary changes and original prices.
You might also need
How It Works
Your manager needs 73% of a $420,000 target — enter 73 and 420000, result: $306,600. A store advertises 35% off a $120 jacket — enter 35 and 120, you save $42 and pay $78. The remainder is always shown automatically.
Result = (% ÷ 100) × Number(15 ÷ 100) × 200 = 30 | Remainder: 170You scored 42 out of 56 — enter 42 and 56, result: 75%. Your team closed 31 of 40 sales calls — result: 77.5% conversion rate. The formula divides the part by the whole, then scales to 100.
Percentage = (X ÷ Y) × 100(30 ÷ 200) × 100 = 15%Electricity bill from $148 to $186 — enter 148 and 186, result: +25.68%. Portfolio from $12,000 to $10,800 — result: −10%. Always divide by the old value, never the new one.
Change = ((New − Old) ÷ |Old|) × 100((250 − 200) ÷ 200) × 100 = +25%Paid $85 after a 15% discount — $85 is 85% of original. Enter 85 and 85, result: $100. Paid $42 tax at 8.5% — enter 42 and 8.5, result: $494.12 pre-tax. This mode works backwards from the result.
Whole = Part ÷ (% ÷ 100)30 ÷ (15 ÷ 100) = 200 ✓ 15% of 200 = 30Salary of $1,200 with a 10% raise — enter 1200 and 10, select Increase, result: $1,320. A $500 item with 20% off — enter 500 and 20, select Decrease, result: $400. The amount added or deducted is shown automatically.
Result = Number × (1 ± % ÷ 100)200 × (1 + 15 ÷ 100) = 230 | 200 × (1 − 15 ÷ 100) = 170Quick Reference
Common percentage calculations — results you can verify instantly.
What is X% of Y?
15% of 200
30
X is what % of Y?
30 is ?% of 200
15%
Percentage change
200 → 250
+25%
Find original
30 is 15% of ?
200
Increase
200 + 15%
230
Decrease
200 − 15%
170
X is what % of Y?
42 is ?% of 56
75%
What is X% of Y?
10% of 150
15
Tips & Shortcuts
Find 10% by moving the decimal one place left, then scale: 15% = 10% + half of 10%, 20% = double 10%.
To undo a % increase, divide — not subtract. $125 after +25% → original = $125 ÷ 1.25 = $100.
Sequential % changes multiply, not add. +10% then +8% = 1.10 × 1.08 − 1 = 18.8%, not 18%.
Always divide by the OLD value for % change. $80 to $96: (96−80)÷80 = 20%, not ÷96 = 16.67%.
A percentage above 100% is valid. 150% of $80 = $120. It simply means the result exceeds the original.
Common Mistakes
Entering 0.15 instead of 15 for "15%"
This calculator expects whole numbers. 0.15 means 0.15% — a result 100× smaller. Always enter 15, not 0.15.
Confusing "15% of $200" with "15% off $200"
"15% of $200" = $30 (the amount). "15% off $200" = $170 (final price). The calculator shows both — result and remainder — automatically.
Entering From and To values in reverse for % Change
Always enter the starting (old) value first, the ending (new) value second. Reversing them flips the sign and changes the magnitude.
Reversing a % increase by subtracting the same %
Price increased 20% to reach $120. Original is NOT $120 − 20% = $96. Correct: $120 ÷ 1.20 = $100. Use "X is Y% of what?" mode instead.
Adding sequential percentage changes
Two 10% raises ≠ 20%. Correct: 1.10 × 1.10 − 1 = 21%. Percentages always compound — they multiply, never add.
Frequently Asked Questions
15% of 200 = 30. Formula: (15 ÷ 100) × 200 = 30. The remainder is 170 (85%). Practical use: a 15% tip on a $200 restaurant bill is exactly $30.
$100 + 50% = $150. Then 50% of $150 = $75 — not $100. The decrease applies to a larger base. To return to $100 from $150 you need a 33.3% decrease. Formula: (1+r)(1−r) = 1−r² always results in a net loss.
A percentage point is the arithmetic difference. Percent change is the relative change. If interest rates rise from 4% to 6%, that is 2 percentage points but a 50% relative increase. Financial news often mixes them up.
Use "X is Y% of what?" mode. Paid $85 after 15% off — $85 is 85% of the original. Enter 85 and 85 → $100. Or: $42 tax at 8.5% rate → pre-tax: $494.12. Formula: Part ÷ (% ÷ 100) = Whole.
Because each percentage applies to a different base. A salary rising 5% then 8% = 1.05 × 1.08 − 1 = 13.4%, not 13%. A $10,000 investment at 7% per year for 20 years reaches $38,697 — not $24,000.
Use "Increase / Decrease" mode. $200 + 15% = $230. $200 − 15% = $170. Formula for increase: Number × (1 + % ÷ 100). The amount added or deducted is shown automatically.
For 10%: move the decimal one place left. For 20%: double the 10%. For 15%: find 10% then add half. For 25%: divide by 4. For 5%: halve the 10% value. These cover most daily calculations in under 5 seconds.
Related Calculators
Percent Off Calculator
Find the sale price after a percentage discount.
Ratio Calculator
Simplify ratios and find equivalent ratios.
VAT Calculator
Add or remove VAT from any price for any country or custom VAT rate instantly.
Simple Interest Calculator
Calculate interest earned on a principal without compounding.
Finance Calculator
All-in-one: PV, FV, PMT, rate, and period solver.
Scientific Calculator
Full scientific calculator with trig, log, and advanced functions.