Percentage Calculator is a free online tool to calculate percentages.

Percentage of a Number

Result :

[Answer]

What Percent of a Number

Result :

[Answer]%

Percentage Increase or Decrease

Result :

[Answer]% Increase/Decrease or No Change

Know Us Better

Our percentage calculator is a fast, accurate tool that solves every common percent problem: percentage of a number (e.g., what is 18% of 250), what percent (e.g., 45 is what percent of 120), and percentage increase or decrease (e.g., price change from 79.99 to 65.49). It’s built for students, teachers, shoppers, small-business owners, and analysts who want instant, reliable answers on mobile or desktop.

Enter values as plain numbers (1250) or friendly input like 1,250 and 12.5%. The percentage calculator cleans your input automatically and displays a clear, formatted result with the right formula:

  • Percentage of a Number → Result = (Percent ÷ 100) × Total
  • What Percent of a Number → Percent = (Part ÷ Total) × 100
  • Percentage Change → Change% = ((New − Old) ÷ |Old|) × 100

Why Use a Percentage Calculator?

Manual percentage math is error-prone—especially when mixing commas, decimals, and edge cases like totals of zero. This percentage calculator prevents mistakes, handles edge cases (e.g., undefined or infinite changes), and gives you both the result and the reasoning. It’s ideal for:

  • Shopping & Discounts: 15%–70% off sale prices, final cost after multiple discounts, tip & tax.
  • Grades & Exams: converting points to percent, computing weighted scores.
  • Finance: percentage change, growth rates, ROI, APR components.
  • Business: conversion rates, analytics KPIs, YoY/ MoM shifts, margins & markup.
  • Science & Data: proportions, experimental yields, error percentages.

How to Use the Percentage Calculator (Step-by-Step)

  1. Choose your problem type (Percentage of a Number, What Percent, or Percentage Change).
  2. Enter values using whole numbers or decimals; commas and “%” symbols are OK.
  3. Click Calculate to get the exact answer with the formula shown.
  4. Adjust inputs as needed to compare scenarios (e.g., different discounts or goals).

Quick Examples

  • What is 18% of 250? → (18 ÷ 100) × 250 = 45
  • 45 is what percent of 120? → (45 ÷ 120) × 100 = 37.5%
  • Change from 80 to 60: → ((60 − 80) ÷ 80) × 100 = −25% (25% decrease)
  • Change from 50 to 65: → ((65 − 50) ÷ 50) × 100 = 30% (30% increase)

Discounts, Tax, Tips & Stacked Percentages

Real-world price math often stacks percentages. A 20% discount then 8% tax is not the same as 12% overall: we apply each step in order. Try sequences with the percentage calculator to see true final prices.

  • After Discount: Sale = Price × (1 − discount%)
  • After Tax/Tip: Total = Amount × (1 + rate%)
  • Multiple Discounts: Price × (1 − d1) × (1 − d2) × …

Margin vs. Markup (Business Percentages)

  • Markup % (based on cost): ((Price − Cost) ÷ Cost) × 100
  • Margin % (based on price): ((Price − Cost) ÷ Price) × 100

Use the percentage calculator to compute either quickly—helpful for pricing, quotes, and profitability checks.

Convert Between Percent, Decimal & Fraction

  • Percent → Decimal: divide by 100 (e.g., 12% → 0.12)
  • Decimal → Percent: multiply by 100 (e.g., 0.075 → 7.5%)
  • Percent → Fraction: put over 100 and simplify (e.g., 25% → 25/100 → 1/4)

Common Mistakes the Percentage Calculator Avoids

  • Using difference instead of percent change (forgetting to divide by the original value).
  • Treating sequential discounts as additive (e.g., 20% + 10% ≠ 30%).
  • Dividing by zero when the total is 0 (we show “undefined” or “infinite increase” clearly).
  • Misreading commas, spaces, or percent symbols (we sanitize input automatically).

Quick Help & Answers

A percentage expresses a number as a fraction of 100 (symbol “%”). Example: 25% means 25 out of 100.

Use percent = (part ÷ total) × 100. Example: 20 red apples out of 50 total → 40%.

Use (percent ÷ 100) × total. Example: 18% of 250 = (0.18) × 250 = 45. The percentage calculator does this instantly.

Use ((New − Old) ÷ |Old|) × 100. Positive means increase; negative means decrease.

Yes. Enter values like 1,250 or 12.5%; the tool sanitizes input automatically.

“What percent” is undefined if the total is 0. For percentage change, going from 0 to a positive number is an infinite increase; the calculator labels this clearly.

Apply them in order using multipliers: Price × (1 − d1) × (1 − d2) × … × (1 + tax). The percentage calculator shows the true final price.

Markup% = ((Price − Cost) ÷ Cost) × 100. Margin% = ((Price − Cost) ÷ Price) × 100. Use the calculator to compute either quickly.

Percent → Decimal: divide by 100 (12% → 0.12). Decimal → Percent: multiply by 100 (0.075 → 7.5%). Percent → Fraction: put over 100 and simplify (25% → 1/4).

Yes. It is mobile-friendly and optimized for quick use on phones and tablets.