Percentage Calculator

Calculate percentages, discounts, tips, tax, markup, and percentage changes with instant results

✓ Basic Percentages ✓ Discounts & Tips ✓ Percentage Change

Basic Percentage Calculator

What is X% of Y?

% of
Result:
50

X is what % of Y?

is what % of
Result:
25%

X% of what is Y?

% of what is
Result:
200

Common Examples

Quick Reference

Common Percentages:
10% = 0.1
25% = 0.25
50% = 0.5
75% = 0.75
Fractions:
1/4 = 25%
1/3 ≈ 33.33%
1/2 = 50%
3/4 = 75%

Percentage Calculator: Quick Answers, Real-World Uses, and Smart Shortcuts

Percentages are everywhere — from discounts and tips to grade conversions, interest rates, and data analysis. Our Percentage Calculator helps you compute percent changes, find what percentage one number is of another, calculate percentage points vs percent change, and solve real-world problems like sales discounts, tax add-ons, and tip splitting. This guide explains the underlying formulas, step-by-step examples, productivity shortcuts, and how to pair percentage calculations with related tools such as the Fraction Calculator, Compound Interest Calculator, and Salary After Tax Calculator.

What the Percentage Calculator Does

  • Compute x% of y (e.g., 15% of 240 = 36).
  • Find what percent one number is of another (e.g., 36 of 240 = 15%).
  • Calculate percentage change (increase/decrease) and percentage points.
  • Convert between fractions, decimals, and percentages quickly.
  • Handy tools: split tips, calculate discounts and markups, and reverse percentage (find original price before tax).

Why precise percent math matters

Small percentage mistakes are common but can cost money or lead to miscommunication (e.g., confusing 10 percentage points with 10% relative change). Use the tool for budgeting, shopping, reporting, and schoolwork to avoid costly rounding errors.

Quick Concepts: Percent vs Percentage Point

Two similar-sounding terms are often confused:

  • Percent (%): A relative change. If a value goes from 50 to 100, that's a 100% increase.
  • Percentage point: An absolute difference between two percentage values. E.g., moving from 10% to 15% is a 5 percentage point increase (which is a 50% relative increase).

Pro Tip

Use the calculator's dedicated fields for percent change and percentage-point conversion to keep reports and communications precise.

Basic Percentage Formulas — The Cheatsheet

  • To find x% of y: (x ÷ 100) × y. Example: 15% of 240 = 0.15 × 240 = 36.
  • To find what percent a is of b: (a ÷ b) × 100. Example: What percent is 36 of 240? → (36 ÷ 240) × 100 = 15%.
  • Percentage change (increase/decrease): ((new − old) ÷ old) × 100. Example: 120 → 150 = ((150 − 120) ÷ 120) × 100 = 25% increase.
  • Reverse percentage (find original price before tax/discount): original = final ÷ (1 ± rate). Example: If $108 is after 8% tax, original = 108 ÷ 1.08 = 100.

Example Scenarios: Real-World Walkthroughs

1) Shopping Discount + Sales Tax

You see a jacket priced $120 with 25% off and a 7% sales tax. Compute the final price:

  1. Discount: 25% of 120 = 0.25 × 120 = $30 → sale price = 120 − 30 = $90.
  2. Tax: 7% of 90 = 0.07 × 90 = $6.30 → final price = 90 + 6.30 = $96.30.

The Percentage Calculator can perform both steps automatically and show the intermediate results for clarity.

2) Tip Splitting

Dinner bill $72.50 split among 4 people with a 20% tip:

  • Tip = 20% × 72.50 = 14.50 → total = 87.00 → each person pays = 87 ÷ 4 = $21.75.

Use the “split” feature to round per-person shares and show exact cents or rounded splits.

3) Percent Change for Reports

Your website traffic went from 2,400 to 3,000 visitors month-to-month. Relative percent change = ((3000 − 2400) ÷ 2400) × 100 = 25% increase. If you're reporting percentages in dashboards, the calculator returns results and the underlying raw numbers to avoid misinterpretation.

Percent vs Percentage Points — Why It Matters in Communications

If a bank’s interest rate moves from 2% to 3%:

  • Change in percentage points = 1 percentage point.
  • Relative percent change = (1 ÷ 2) × 100 = 50% increase in the rate.

Use the calculator to display both values so your audience understands whether you mean absolute (points) or relative changes (percent).

Discounts vs Markups: The Reverse Math

Markups and discounts are not symmetric. If an item priced at $100 is discounted 20% (→ $80), a 20% markup on $80 only returns it to $96, not $100. For markup from cost to price use markup% = ((price − cost) ÷ cost) × 100. The Percentage Calculator handles both directions and shows the reverse calculation (what discount would return to original price).

Fractions, Decimals & Percentage Conversions

Converting formats is frequent in exams and finance:

  • To convert fraction → percent: (a ÷ b) × 100. Example: 3/8 = 0.375 → 37.5%.
  • Decimal → percent: multiply by 100 (0.08 → 8%).
  • Percent → decimal: divide by 100 (7% → 0.07).

For recurring decimals or complex fractions, combine with the Fraction Calculator to preserve exact values.

Roundings & Presentation: Business-Friendly Rules

Decide on rounding rules up front for consistency in reports:

  • Percentages to one decimal for dashboards (e.g., 12.3%).
  • Percentage points shown separately from percent change and labeled clearly.
  • Show raw numbers and denominators when possible to avoid misleading conclusions.

Productivity Shortcuts & Mental Math Tricks

  • 10% of a number → divide by 10; 5% → divide by 20; 1% → divide by 100.
  • 15% = 10% + 5% (good for quick discounts). Example: 15% of 200 = 20 + 10 = 30.
  • To apply successive percentages multiply factors: +20% then −10% = ×1.20 ×0.90 = ×1.08 net +8%.
  • For quick reverses, if final price after tax is P and tax is r, original = P ÷ (1 + r).

How Percentage Calculations Help with Finance & Investing

Percentages are core to returns, fees, and growth. Use the Percentage Calculator to:

  • Calculate annualized returns and month-to-month percent changes, then feed results into the Compound Interest Calculator for projections.
  • Compare fee structures as percentages of assets under management to see long-term drag.
  • Compute tax-withholding percentages and net salary after tax with the Salary After Tax Calculator.

Frequently Asked Questions

What’s the difference between percent change and percentage points?

Percent change is relative ((new − old) ÷ old × 100). Percentage points are the absolute difference between two percentages (e.g., 3% → 5% = 2 percentage points).

How do I remove tax from a final price?

Divide the final price by (1 + tax rate). Example: $135 with 8% tax → original = 135 ÷ 1.08 = 125.

How do I calculate a percent increase given old and new values?

Use ((new − old) ÷ old) × 100. If old = 80 and new = 100 → ((100 − 80) ÷ 80) × 100 = 25% increase.

Why does 50% off then 20% off give a different result than 70% off?

Percent discounts apply multiplicatively to the remaining price, not additively. 50% off leaves 50%, then 20% off leaves 80% of 50% = 40% of original (net 60% off), not 30% off.

Can the percentage calculator help with grades and GPA?

Yes — convert marks to percentages, compute weighted averages, and check percent contribution of assignments. For GPA-specific planning use the GPA Calculator.

Do Percent Math Faster — Avoid Costly Mistakes

Use the Percentage Calculator to solve discounts, markups, percent change, and conversions accurately in seconds.

Percentage Calculator Fraction Calculator Compound Interest Salary After Tax All Calculators

Related reading: Percentage Tricks • Student Calculator Guide