Skip to content
TypeParser
All tools

Percentage Calculator

Common percentage operations.

beats calculator.net edge: Four operations side-by-side
X% of Y
% of = 30
X is what % of Y
is 20% of
% change from X to Y
→ = +25%
X plus / minus Y%
± % = 115 / 85
Guide

About Percentage Calculator

All four common percentage operations side-by-side — X% of Y, X is what % of Y, percent change between two numbers, percent increase/decrease. Formulas shown alongside results so the math is auditable. Useful for quick math during meetings, finance, shopping, or stats.

The four operations

  1. X% of Y — (X/100) × Y. Use for: tip on a bill, discount on a price, sales tax.
  2. X is what % of Y — (X/Y) × 100. Use for: market share, pass rate, percentile.
  3. Percent change — ((new - old) / old) × 100. Use for: growth, return, rate of change.
  4. Percent increase / decrease — Y × (1 ± P/100). Use for: applying a raise, applying a discount.

Common workflows

Tip a meal. Bill 67.50, tip 18%: 67.50 × 0.18 = 12.15. Total 79.65.

Year-over-year revenue. Last year 1.2M, this year 1.5M: (1.5 - 1.2) / 1.2 = 25% growth.

Sales tax. 145 × 1.08875 = 157.87 (NYC tax of 8.875%).

Discount finally cheap? Sticker 89.99, 30% off: 89.99 × 0.70 = 62.99.

Performance bonus. Salary 95k, 8% raise: 95000 × 1.08 = 102,600.

Why a tool

The math is one line each, but having all four pinned beats opening a calculator app for 40 seconds of reasoning.

Frequently asked questions

20% of 150?
30. The formula is (percent / 100) × value.
30 is what percent of 150?
20%. Formula: (part / whole) × 100.
From 100 to 125, what percent change?
+25%. Formula: ((new - old) / old) × 100.
Discount on 250 by 15%?
Final price 212.50. Formula: value × (1 - percent/100).
Difference between change and difference?
Change is asymmetric — uses old as base. Difference is symmetric — uses average. Percent change is more common in finance and growth metrics.
Compound percent?
Not in this tool. For repeated growth (interest), use the Loan Calculator for compound math.
How do I calculate a grade or test percentage?
Use "X is what percent of Y": (points earned / total points) × 100. 43 out of 50 is (43/50)×100 = 86%. Enter the earned score and the maximum and the tool returns the percentage — the same math whether it's a test, quiz, or overall grade.
How do I do percentages on a calculator?
For X% of Y, multiply then divide by 100: 150 × 20 ÷ 100 = 30 (or press the % key after 150 × 20). To add a percentage (tax, tip): value × (1 + p/100); to subtract (a discount): value × (1 − p/100). This tool shows the formula beside each result so you can follow the steps.

Related tools

Last updated: 2026-07-04