Percentage Calculator
Four percentage problems in one place: what is X% of Y, X is what percent of Y, percentage increase or decrease, and the percent change between two numbers.
How to use the Percentage Calculator
- Choose the mode that matches your question — percent of, percent change, or what percent.
- Type the two numbers into the fields.
- The answer updates as you type; copy it with one tap.
About the Percentage Calculator
Percentage questions look simple until you have to decide which of the four forms you actually need — and mixing up percentage change with percentage points is one of the most common everyday maths mistakes. Each mode here is labelled in plain language so you pick the sentence that matches your problem rather than remembering a formula. Typical uses are exam marks, salary rises, sale prices, and comparing this month's figures with last month's.
Frequently asked questions
How do I calculate a percentage increase?
Subtract the old value from the new value, divide by the old value, then multiply by 100. Use the increase/decrease mode above and it does this for you.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100 — for example 45 out of 60 is 75%. Use the 'X is what percent of Y' mode.
What is the difference between percent change and percentage points?
Percent change is relative to the starting value; percentage points are a plain subtraction between two percentages. Going from 20% to 25% is a 5 percentage point rise but a 25% increase.
Related free tools
- Pregnancy Due Date Calculator — Estimated due date, current week & trimester from LMP.
- GPA / CGPA Calculator — Semester GPA on the 4.0 scale — and your updated CGPA.
- Age Calculator — Exact age in years, months, days — plus next birthday.
- BMI Calculator — Body mass index with health category.
- Date Difference — Days, weeks and working days between two dates.
- Aspect Ratio Calculator — Scale dimensions while keeping proportions.