How do I calculate a percentage increase?

Use the formula (New minus Old) divided by Old, multiplied by 100. If sales rise from $1,000 to $1,200, the increase is (1200 minus 1000) divided by 1000, times 100, which equals 20 percent. The calculator does it for you when you supply the old and new values, and a negative result simply means a decrease.

What's the difference between percentage change and percentage points?

This distinction trips up news reports constantly. A rate moving from 5 percent to 7 percent is a two percentage point change in absolute terms, but a 40 percent change relative to the starting value because (7 minus 5) divided by 5 equals 0.4. Make sure you compute and label the one that fits the context you're discussing.

Can I calculate compound percentage growth?

Yes. Over N periods at X percent per period, the total comes from original times (1 plus X over 100) to the Nth power. Ten years at 10 percent annual growth multiplies the original by 1.10 to the 10th, which works out to about 2.59 — a 159 percent gain rather than the 100 percent you'd naively guess.

How do percentages work in tipping?

Tip equals the bill multiplied by the percentage divided by 100. A 20 percent tip on $50 is 50 times 0.20, which is $10, for a total of $60. The 'percentage of' operation handles this directly, and some apps show ranges like 15 to 20 percent so you can pick a comfortable amount.

What about discount and sale prices?

The discount price is the original multiplied by (1 minus discount over 100). 30 percent off $100 leaves $70, saving you $30. For stacking discounts apply them sequentially: 40 percent off followed by an additional 25 percent off works out to $100 times 0.60 times 0.75, which is $45 — a 55 percent total discount, not the 65 percent you'd get from naive addition.

Are negative percentages handled?

Yes, mathematically. A -25 percent change means a 25 percent reduction. 'Reduced by -25 percent' is a double negative meaning a 25 percent increase. Be careful with phrasing in source documents because the calculator does exactly what the math says, even when the wording is awkward.

No. The math runs in your browser, so sensitive calculations — salary negotiations, tax planning, financial modeling — never leave your device for third-party logging.

Percentage Calculator

Calculate percentages online with increase, decrease, and ratio modes. Free percentage calculator for discounts, tips, and math.

Calculators

Instant results

What is X% of Y?

What is% of?

X is what % of Y?

is what % of?

X is Y% of what?

is% of what?

Percentage Change

Fromto

Increase/Decrease by Percentage

by%

Percentage Formulas

X% of Y: (X/100) × Y

X is what % of Y: (X/Y) × 100

% Change: ((New - Old) / Old) × 100

Increase by X%: Value × (1 + X/100)

How to Use Percentage Calculator

Choose calculation type

Start by choosing the operation you actually need — 'percent of', 'what percent', 'percentage change', or the reverse calculation that recovers the original value when you only know the result and the rate.

Enter values

Punch in the numbers the operation requires. Most calculators auto-detect which inputs they need based on the chosen operation, so the form simplifies as soon as you pick a mode.

View result

The answer appears instantly along with the formula behind it. Reading the formula is a quick way to confirm you picked the right operation rather than the right answer to the wrong question.

Copy or use

Click Copy to drop the result into another document, or carry the insight straight into a tip calculation, sale negotiation, salary discussion, or any other percentage-driven decision you're working through.

When to Use Percentage Calculator

Tipping at restaurants

Working out 15, 18, or 20 percent of a dinner bill in your head can be error-prone after a long meal. A quick calculation gives you the exact figure, and most calculators offer round-up options for cash gratuity or split the total cleanly when several people are sharing the bill.

Salary negotiations and raises

Salary conversations live or die on the framing. A $5,000 raise on $80,000 is 6.25 percent, while a 5 percent raise on $100,000 is exactly $5,000. Translating between dollar amounts and percentages helps you compare competing offers and decide whether a number you're being offered is generous or quietly underwhelming.

Sales tax and final pricing

You'll often want either the post-tax price or the pre-tax price, depending on the receipt. Computing $108 divided by 1.08 to recover $100 is the reverse calculation that expense reports, business pricing, and budget tracking all need at some point — and it's much easier with a calculator than mental math.

Statistics and data analysis

Converting raw counts into percentages turns dry numbers into something a stakeholder can absorb. '127 of 800 users converted' means more when you can also say 15.875 percent in the next sentence. The same arithmetic underpins A/B test reporting, demographic breakdowns, and any side-by-side comparison of differently sized groups.

Percentage Calculator Examples

Tip calculation

Input

Bill: $52.40\nTip: 18%

Output

Tip: $9.43\nTotal: $61.83

18 percent of $52.40 works out to exactly $9.43, which makes the total $61.83. The calculator returns the precise figure, and you can round up to a whole dollar for cash gratuity if you prefer that style of tipping.

Percentage change

Input

Old: 200 visits/day\nNew: 250 visits/day

Output

Increase: +25%

The formula is (250 minus 200) divided by 200, multiplied by 100, which gives a 25 percent increase. The same calculation drives traffic dashboards, fitness tracking, and sales reports — and remember, swapping the old and new values flips the sign and changes the magnitude.

Reverse percentage

Input

Sale price: $42\nDiscount: 30%

Output

Original price: $60

Dividing $42 by 0.70 (which is 1 minus the 30 percent discount) reveals the original $60 price. The same arithmetic recovers a pre-tax amount from a tax-inclusive total whenever a receipt only shows the final number.

Tips & Best Practices for Percentage Calculator

1.Don't confuse percentage points with percentage change. Going from 5 percent to 7 percent is two percentage points, but it's also a 40 percent increase. Reporters mix these up constantly, so always check which one is actually being claimed.
2.Compound growth multiplies rather than adds. Two consecutive 5 percent increases come out to 10.25 percent because 1.05 times 1.05 equals 1.1025, not 10 percent. The distinction matters enormously over long horizons in investing or population growth.
3.Sales tax is normally applied to the pre-tax base, so to recover the pre-tax price from a tax-inclusive total, divide by 1 plus the tax rate. That's the reverse calculation that catches people out at expense report time.
4.Three formulas cover most cases. 'A is X percent more than B' becomes A equals B times (1 plus X over 100); 'A is X percent less' uses (1 minus X over 100); and 'A is X percent of B' is just B times X over 100.
5.Match precision to audience. Reporting 23.4567 percent growth is mathematically honest but harder to absorb than 23 percent. One or two decimals is usually the right amount of detail for general communication.
6.Percentages alone can mislead with tiny samples. A jump from 2 out of 4 to 3 out of 4 is technically a 50 percent improvement, but the underlying numbers are too small to draw any real conclusion. Always show absolute values alongside the percentage.

Frequently Asked Questions

It covers the full set of common percentage operations. You can ask what percent of X is Y (50 percent of 200 is 100), what percent Y is of X (50 is 25 percent of 200), percentage increases and decreases, the percentage difference between two values, and reverse percentages where you know the result and want the original (Z is 25 percent of what number is 4Z).

Percentage Calculator

What is X% of Y?

X is what % of Y?

X is Y% of what?

Percentage Change

Increase/Decrease by Percentage

Percentage Formulas

How to Use Percentage Calculator

Choose calculation type

Enter values

View result

Copy or use

When to Use Percentage Calculator

Tipping at restaurants

Salary negotiations and raises

Sales tax and final pricing

Statistics and data analysis

Percentage Calculator Examples

Tip calculation

Percentage change

Reverse percentage

Tips & Best Practices for Percentage Calculator

Frequently Asked Questions

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