Percentage Calculator
WEBWork out percentages, increases, decreases and 'what percent' in one tap.
What is the Percentage Calculator tool?
This percentage calculator handles the three percent questions people actually ask, each with its own mode: what is X% of a number, X is what percent of Y, and the percentage change from one value to another. Type two numbers and the answer appears instantly — no formulas to remember, no rearranging equations. Percent increase and decrease are simply the change mode with a sign, so it tells you both the direction and the size of the move.
A quick worked example: to find 15% of 200, choose the '% of' mode and enter 15 and 200 — the result is 30. To find what percent 45 is of 180, the second mode gives 25%. And going from 80 to 100? The change mode shows +25%. The same three modes cover discounts, tax, tips, exam grades, salary raises and statistics — it is the one calculator behind most everyday percent questions.
Everything is calculated client-side in your browser: it is free, needs no sign-up, keeps working offline once the page has loaded, and nothing you type leaves your device. The page is built phone-first with big inputs, and in Arabic it renders Arabic-Indic digits properly — something most percent calculators never bother with. For sale prices specifically, Carbide's discount calculator shows the price after discount and the amount saved in one dedicated screen.
How to use the Percentage Calculator
- Pick a mode: '% of', 'is what %' or '% change'.
- Enter the first number — for '% of' this is the percentage, for example 15.
- Enter the second number — the base it applies to, for example 200.
- Read the result instantly: 15% of 200 is 30.
- Switch modes any time to ask the reverse question about the same numbers.
Frequently asked questions
How do I calculate 20% of a number?
Multiply the number by 0.20 — so 20% of 350 is 70. In the tool, choose the '% of' mode, enter 20 and 350, and the result appears instantly.
How do I work out what percent one number is of another?
Divide the part by the whole and multiply by 100: 45 ÷ 180 × 100 = 25%. The 'is what %' mode does this for you — enter the two numbers and read the percentage.
What is the percentage change formula?
Percentage change = (new − old) ÷ old × 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = +25%; a negative result means a decrease. The '% change' mode applies the formula automatically.
How do I calculate my grade percentage?
Divide your score by the total marks and multiply by 100 — scoring 42 out of 60 is 42 ÷ 60 × 100 = 70%. Use the 'is what %' mode with your score and the total.
Is the percentage calculator free?
Yes — completely free, with no sign-up, no account and no limit on how many calculations you run.
Is what I enter private?
Yes. All three modes are computed in your browser — nothing is sent to a server — and the tool keeps working offline once the page has loaded.
Do I need this instead of a normal calculator?
A plain calculator can answer all three questions if you remember the formulas and key them in the right order. This tool puts each formula behind a labelled mode, so there is nothing to memorize and nothing to rearrange — you just type the two numbers.
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