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Free Percentage Calculator Online: Solve Any Percent Problem Instantly

Calculator and financial documents for percentage calculations
Published: June 8, 20265 min read

Percentage problems come up constantly. What is 15% of 2,400? A product was 3,500 and is now 2,800 -- what percentage discount is that? Your salary went from 80,000 to 95,000 -- what is the percentage increase? These are quick calculations but they trip people up because the formula changes depending on what you are trying to find.

A free online percentage calculator handles every variation instantly. This guide explains the four main types of percentage problems and how to solve each one without doing the math manually.


The 4 Types of Percentage Problems

What is X% of Y?

What is 20% of 500? = 100

Discounts, tax, tips

X is what % of Y?

75 is what % of 300? = 25%

Test scores, ratios

% increase from X to Y

100 to 130 = 30% increase

Salary, prices, growth

% decrease from X to Y

500 to 350 = 30% decrease

Sales, weight loss, drops


How to Calculate Percentages Online for Free

  1. 1

    Go to toolzgo.com/tools/math-tools/percentage-calculator

  2. 2

    Select the type of percentage problem you need to solve

  3. 3

    Enter the known values into the fields

  4. 4

    The answer appears instantly as you type

  5. 5

    Copy the result or use the explanation shown below the answer


Percentage Formulas for Reference

ProblemFormula
X% of Y(X / 100) x Y
X is what % of Y(X / Y) x 100
Percentage increase((New - Old) / Old) x 100
Percentage decrease((Old - New) / Old) x 100
Original before % increaseFinal / (1 + Rate/100)
Original before % decreaseFinal / (1 - Rate/100)

Real-World Examples

Shopping discounts

A shirt costs 2,400 PKR. There is a 30% sale. The discount is 720 PKR and you pay 1,680 PKR. Use the "What is X% of Y?" mode to find the discount amount.

Exam results

You scored 74 out of 90 marks. To find your percentage: 74 / 90 x 100 = 82.2%. Use the "X is what % of Y?" mode for this.

Salary negotiation

Your current salary is 85,000. You want to ask for a 20% raise. That is 17,000 more, so you should ask for 102,000. Use "What is X% of Y?" to calculate the raise amount.

Tracking growth

Your website had 1,200 visitors last month and 1,850 this month. The growth rate is ((1850 - 1200) / 1200) x 100 = 54.2%. Use the percentage increase mode.

Frequently Asked Questions

What is the difference between percentage increase and percentage point increase?

If interest rates go from 5% to 8%, the percentage point increase is 3 (simple subtraction). The percentage increase is 60% ((3/5) x 100). They sound similar but mean very different things.

How do I find the original price before a discount?

Divide the sale price by (1 - discount rate). For example, if you paid 1,400 after a 30% discount: 1400 / 0.70 = 2,000. That was the original price.

Can I calculate GST or VAT with this tool?

Yes. To find the tax-inclusive price, use "What is X% of Y?" to find the tax amount, then add it to the original price. For 17% GST on 1,000 PKR: 17% of 1,000 = 170, so total is 1,170.

How accurate is the calculation?

The calculator uses standard JavaScript floating-point arithmetic and rounds to 2 decimal places for practical display. For financial calculations requiring more precision, the raw result is available.

More calculators: discount calculator, loan calculator, tip calculator, all free.


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