Calculator
Percentage Calculator
Three ways to solve any percentage problem. All results update in real time.
Mode 1
What is P% of V?
Result
—
Formula: P ÷ 100 × V
Mode 2
X is what % of Y?
Result
—
Formula: (X ÷ Y) × 100
Mode 3
X is P% of what?
Result (base)
—
Formula: X ÷ (P ÷ 100)
How it works
The three percentage formulas.
Find P% of V
25% of 80 = 25 ÷ 100 × 80 = 20 Multiply the value by the percentage, then divide by 100.
Find what %
30 of 150 = (30 ÷ 150) × 100 = 20% Divide the part by the whole and multiply by 100 to get the percentage.
Find the base
50 is 25% of 200 Divide the part by the percentage (as a decimal). 50 ÷ 0.25 = 200.
What Does This Percentage Calculator Do?
This percentage calculator solves three distinct problems using a single formula. Whether you need to find a percentage of a number, reverse-engineer a base value, or figure out what percent one number represents of another — all three are here in one place.
Most percentage questions in everyday life fall into one of these three patterns:
- You know the percentage and the total, and want the part → Module 1
- You know the part and the total, and want the percentage → Module 2
- You know the part and the percentage, and want the total → Module 3
Just pick the module that matches what you already know, fill in the two fields, and the result appears before you finish typing.
How Each Module Works
Module 1 — What is P% of V?
This is the most common percentage question. You have a total and a percentage, and you want the actual amount. Formula: Result = (P ÷ 100) × V.
Example: What is 18% of 2,500? → (18 ÷ 100) × 2,500 = 450. This is how GST on a product, commission on a sale, or interest on a loan is calculated.
Module 2 — X is what % of Y?
Use this when you have two numbers and want to express one as a percentage of the other. Formula: Percentage = (X ÷ Y) × 100.
Example: You scored 72 out of 90 on a test. What percent did you get? → (72 ÷ 90) × 100 = 80%. Useful for exam marks, survey results, market share, and budget usage.
Module 3 — X is P% of what?
This module reverses the equation. You know the part and the percentage it represents, but not the original whole. Formula: Base = X ÷ (P ÷ 100).
Example: 45 is 15% of what number? → 45 ÷ 0.15 = 300. Handy when you know a sale price and the discount percent but want the original price.
Real-World Uses for Each Module
| Module | Common Situations |
|---|---|
| Module 1 (P% of V) | Tax on a bill, salary deduction, scholarship value, commission on sales |
| Module 2 (X is what % of Y) | Exam scores, attendance percentage, budget vs. actuals, market share |
| Module 3 (X is P% of what) | Original price before discount, pre-tax amount, base salary before deduction |
The Core Formula Behind All Three
All three modules are built from one equation: Percentage = (Part ÷ Whole) × 100. Each module rearranges it to solve for a different unknown:
- Module 1 solves for the Part: Part = (Percentage ÷ 100) × Whole
- Module 2 solves for the Percentage: Percentage = (Part ÷ Whole) × 100
- Module 3 solves for the Whole: Whole = Part ÷ (Percentage ÷ 100)
You don't need to memorize any of this. The calculator handles the math — but knowing which module maps to which unknown helps you pick the right one fast.
Related guides
For shopping math — finding the sale price after a "30% off" sign — use the Discount Calculator. It handles stacked discounts and lets you reverse-engineer the original price from a sale price. Our guide on how to calculate percentage off explains the formulas in detail.
Tracking a value that changed over time? The Percentage Change Calculator finds the exact percentage increase or decrease between any two numbers. See the guide on how to calculate percentage change for rent, salary, and investment examples.
To find what percent one number is of another with a visual progress bar, use the Percentage of Number calculator. For splitting restaurant bills and calculating tips, the Tip Calculator handles tip amounts and per-person splits.
FAQ
Frequently Asked Questions
Q1What is P% of a number — how does Module 1 work?
Module 1 finds a percentage of any number. Enter the percentage (P) and the value (V) — the calculator multiplies V by P/100 to give you the result. For example, 20% of 350 = 70. It's the go-to tool for finding tax amounts, discounts, commissions, or interest on a loan.
Q2How do I find what percent X is of Y?
Divide X by Y and multiply by 100 — Module 2 does this instantly. Enter your two numbers (the part X and the total Y) and the result is the percentage X represents of Y. For example, 45 out of 180 = 25%. Used for exam results, budget tracking, and market share analysis.
Q3What does "X is P% of what?" mean, and when do I use Module 3?
Module 3 finds the base (original whole) when you only know the part and its percentage. If you know that 60 is 30% of something, Module 3 tells you the "something" is 200. Common uses: recovering original price before a discount, finding pre-tax salary, or reversing a deduction.
Q4What is the basic percentage formula?
The core formula is: Percentage = (Part ÷ Whole) × 100. From this you can derive all three variants used here. Module 1 solves for the Part, Module 2 solves for the Percentage, and Module 3 solves for the Whole. All percentage problems reduce to solving one of these three unknowns.
Q5How do I calculate percentage of marks obtained?
Use Module 2: enter your marks scored as X and the maximum marks as Y. The result is your percentage. For example, 450 out of 600 → (450 ÷ 600) × 100 = 75%. This works for school exams, competitive tests, and grade reports of any kind.
Q6Is this percentage calculator free and accurate?
Yes — fully free, no login or signup required. All calculations run directly in your browser; nothing is sent to any server. Results are mathematically precise to up to 6 decimal places for small numbers, making it reliable for academic, financial, and everyday use.
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