Online Advanced Percentage Calculator

A complete, question-driven percentage calculator covering five formulas: find a percentage, a part, or a whole, and calculate increases and decreases.

Pick the question that matches what you need and fill in its values. You can answer several at once.

What is P% of a value?

%

A value is what percent of a total?

A value is P% of what total?

%

What percent of a value equals a result?

P% of what value equals a result?

%

What is P% of a value?

%

A value out of what total is P%?

%

What value out of a total is P%?

%

A value out of a total is what percent?

What is a value increased by P%?

%

A value plus what percent equals a result?

What value increased by P% equals a result?

%

What is a value decreased by P%?

%

A value minus what percent equals a result?

What value decreased by P% equals a result?

%

Result

Y = P% × X
1 = 10% × 10
P% × X = Y
10% × 10 = 1
Y ÷ X = P%
1 / 10 = 10%
X + (X × P%) = Y
10 + 10% = 11
X − (X × P%) = Y
10 - 10% = 9

What Is This Tool?

This is a comprehensive percentage calculator built around five core formulas, with a plain-English question under each one. Instead of remembering formulas, you simply pick the question that matches your problem, such as 'What is P% of a value?' or 'A value plus what percent equals a result?', enter the numbers you know, and get the answer. It covers finding a percentage, a part, or a whole, plus percentage increases and decreases, and you can answer several questions at once.

How to Use This Tool?

  • Open the formula section that fits your problem.
  • Find the question that matches what you need.
  • Enter the values you already know.
  • Click Calculate to see each answer.

Key Features

  • Covers five percentage formulas in one tool.
  • Offers a plain-English question for every calculation type.
  • Finds a percentage, a part, or a whole value.
  • Calculates percentage increases and decreases.
  • Answers multiple questions in a single calculation.

Examples

  • 10% of 10 is 1.
  • 1 out of 10 is 10%.
  • 10 increased by 10% is 11.
  • 10 decreased by 10% is 9.

Common Use Cases

  • Calculating discounts, taxes, and tips.
  • Finding what percent one number is of another.
  • Working out an original value before a change.
  • Adding or removing a percentage from a price.
  • Solving many kinds of percentage homework problems.

Tips & Best Practices

  • Choose the question by its wording, not the formula.
  • Enter percentages as plain numbers, without the % sign.
  • Use the increase and decrease sections for markups and discounts.
  • You can fill several questions and get all answers at once.
  • Double-check which field is the percentage and which is the value.

Limitations

  • Some questions can't be solved when a value would require dividing by zero.
  • Results are rounded for readability.
  • Each question solves for one unknown at a time.
  • It works with numbers, not units or currencies directly.

Frequently Asked Questions

Do I need to know the formula?
No. Just pick the question that describes your problem, and the tool applies the right formula for you.
What kinds of questions can it answer?
It finds a percentage of a number, what percent one number is of another, the whole from a part, and the result of a percentage increase or decrease.
Can I answer more than one question at once?
Yes. Fill in any questions you need across the sections, and the tool shows an answer for each.
Why is one of my answers missing?
A question only produces an answer when both of its fields are filled with valid numbers.

Key Terminology

Percentage
A number expressed as a fraction of 100.
Part
The portion of a whole that a percentage represents.
Whole
The full base amount that equals 100%.
Percentage increase
Adding a percentage of a value back to that value.
Percentage decrease
Subtracting a percentage of a value from that value.

Quick Knowledge Check

What is 10% of 10?
1 out of 10 is what percent?
What is 10 increased by 10%?