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Free Percentage Calculator

Solve any percent problem in seconds: X percent of Y, percent increase or decrease, sale discounts, tips and more. Instant answers, free forever.

Percent (X)

Value (Y)

Result

20% of 50

Value (Y)

Base (X)

Result

20%

10 is 20% of 50

Original value

New value

Percent increase

25%

From 80 to 100 (difference of 20)

Original price (USD)

Discount (%)

Sale price

$85.00

You save $15.00 (15% off)

Bill amount (USD)

Tip (%)

Split between

Total per person

$35.40

Total with tip: $70.80 · Tip: $10.80

100% Private

All calculations run in your browser. Your numbers are never uploaded or stored anywhere.

No Sign-Up

Use the calculator instantly — no account, no email, no waiting.

Free Forever

Every tool on this site is completely free, with no limits and no hidden fees.

How to Use This Calculator

1
Pick a mode
Choose the tab that matches your problem — X% of Y, percent change, discount, tip, and more.
2
Enter your numbers
Type the values into the fields. Results update live as you type — no button to press.
3
Read the answer
The big result plus a plain-English explanation show exactly what the numbers mean.

Why Use It

Five Calculators in One

Percent of, reverse percent, increase/decrease, discounts and tip splitting — one page covers them all.

Instant Answers

Results update on every keystroke, so experimenting with different numbers is effortless.

Bill Splitting

The tip mode splits the total — tip included — fairly between everyone at the table.

Shopping Made Simple

See the sale price and exactly how much you save on any discount, in USD.

Plain-English Explanations

Each answer comes with a short breakdown, so you understand the math, not just the number.

Mobile Friendly

Large touch-friendly fields and a tab layout that works perfectly on phones.

Frequently Asked Questions

How do I calculate X percent of Y?

Multiply Y by X and divide by 100. For example, 20% of 50 = 50 × 20 ÷ 100 = 10.

How do I calculate percent increase or decrease?

Subtract the original value from the new value, divide by the original value, then multiply by 100. Going from 80 to 100: (100 − 80) ÷ 80 × 100 = 25% increase.

What is the difference between percentage points and percent?

Going from 20% to 25% is a 5 percentage-point increase, but a 25% relative increase (5 ÷ 20 × 100). They measure different things — do not mix them up.

How do I find the original price before a discount?

Divide the sale price by (1 − discount as a decimal). An item at $85 after 15% off originally cost 85 ÷ 0.85 = $100.

What tip percentage is standard in the US?

15–20% at sit-down restaurants is the usual range, with 18–20% being the most common for good service. Takeout and counter service are typically 10% or a flat few dollars.

How do I calculate a grade as a percentage?

Use the “Y is what % of X” mode: divide points earned by total points, then multiply by 100. For example, 85 points out of 100 = 85%.

Are my numbers sent anywhere?

No. Every calculation runs locally in your browser — nothing is uploaded, stored or shared.