PERCENTAGE CALCULATOR
Calculate percentages instantly — what is X% of Y, X is what % of Y, and percentage change between two numbers. No fuss, no clutter.
// What is X% of Y? (e.g. 20% of 80 = 16)
// enter values above to calculate
Contact us to advertise here
// FAQ
FREQUENTLY ASKED QUESTIONS
Q1.How do I calculate what percentage one number is of another?
Divide the part by the whole, then multiply by 100. For example, to find what percentage 25 is of 80: (25 ÷ 80) × 100 = 31.25%. Use the "X IS WHAT %" mode in this calculator to do this instantly.
Q2.How do I calculate X% of a number?
Multiply the number by the percentage divided by 100. For example, 20% of 150 = (20 ÷ 100) × 150 = 30. Alternatively, move the decimal two places left: 20% = 0.20, then 0.20 × 150 = 30. The "X% OF Y" mode handles this automatically.
Q3.How do I calculate percentage change (increase or decrease)?
Subtract the original value from the new value, divide by the absolute original value, then multiply by 100. Formula: ((new − old) / |old|) × 100. A positive result is an increase; negative is a decrease. Example: from 50 to 75 = ((75 − 50) / 50) × 100 = +50% increase.
Q4.What is the difference between percentage increase and percentage difference?
Percentage increase (or decrease) measures change relative to the original value — it has direction (increase vs. decrease). Percentage difference measures how different two values are relative to their average — it has no direction. Use percent change when you have a "before" and "after" value; use percent difference when comparing two peer values.
Q5.How do I add a percentage to a number (e.g. add VAT)?
To add a percentage to a number, calculate X% of the number and add it to the original. Example: adding 20% VAT to £100 — 20% of 100 = 20, so the total is £120. Use the "X% OF Y" mode to find the percentage amount, then add it to your original number.
Q6.How do I find the original number before a percentage was added?
Divide the final number by (1 + percentage/100). Example: a price after 20% VAT is £120. Original price = 120 ÷ 1.20 = £100. This is called "reverse percentage" or "working backwards from a percentage."
// RELATED TOOLS
Calculate monthly payments, total interest, and full amortization schedules with visual charts.
Compare top credit cards for travel rewards, cash back, and credit building. Find your best match.
Calculate tip amounts and split bills among any group. Choose preset or custom tip %, round up totals, and get a per-person breakdown instantly.