Five different percentage calculations in one tool.
Fill in the numbers above to see the result
Multiply the number by 0.20. Example: 20% of 150 = 150 × 0.20 = 30. Or use the "% of Number" tab above.
Percentage change = ((New Value − Old Value) / Old Value) × 100. Use the "% Change" tab for instant results.
Percentage increase = Original + (Original × Rate/100). Example: 200 increased by 25% = 200 + 50 = 250.
A percentage calculator works out percentage-based math quickly and accurately. Percentages come up constantly in everyday life — calculating a discount, working out a tip, figuring a tax amount, finding what fraction one number is of another, or seeing how much something increased or decreased. Rather than remembering the formulas and doing the arithmetic by hand, a percentage calculator gives you the answer instantly across several common types of percentage problems.
There isn't just one percentage calculation — there are several distinct types, and people often mix them up. What is X% of Y? X is what percent of Y? What is the percentage increase or decrease from one number to another? The ConvertDox Percentage Calculator handles each of these as a separate, clearly-labeled calculation, so you pick the question you're actually asking and get the right answer. Everything is computed in your browser, instantly, with no signup.
Work out the sale price when something is 20%, 30%, or 50% off so you know what you'll actually pay.
Calculate a 15%, 18%, or 20% tip on a bill quickly and accurately.
Find the tax portion of a price, or the total including a given tax percentage.
Convert a score like 42 out of 50 into a percentage to understand a result.
Calculate the percentage increase or decrease between an old price and a new one.
Express one figure as a percentage of another for reports, budgets, or comparisons.
Yes, completely free with no signup and no limits on how often you use it.
Multiply the number by the percentage expressed as a decimal. For example, 20% of 150 is 150 × 0.20 = 30. The calculator does this for you.
Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase, a negative one is a decrease. The tool calculates it automatically.
It finds what proportion one number is of another. For example, 30 is what percent of 150? The answer is 20%. Divide X by Y and multiply by 100.
No. All calculations happen in your browser. Nothing you enter is uploaded or stored.
Yes. Use the "percent of" calculation for tips and the discount logic for sale prices — both are common percentage problems the tool covers.