Calculate any percentage: find % of a number, % change between values, or what % one number is of another.
Three percentage calculators in one: find what X% of a number is, work out what percentage one number is of another, or calculate the percentage change between two values. All three panels work independently and results update as you type.
Use whichever of the three panels fits your question and enter the numbers. The answer appears instantly on the right. All three panels are independent — you can use them in any combination.
Most percentage problems are not hard because the maths is hard. They go wrong because the question is framed wrongly. “What is 20% of 85?” is a different question from “85 is what percent of 100?” and both are different again from “a price went from 85 to 100 — what was the percentage increase?” The numbers may be similar, but the logic is not.
This tool splits those three jobs into separate panels so you can use the right calculation instead of forcing one kind of percentage problem into another.
This is the discount, tax, commission, or contribution question. You know the base number and the rate, and you want the resulting amount.
Example: 30% of 85 is 25.50.
This is the score, completion, ratio, or share-of-total question.
Example: 32 out of 40 is 80%.
This is the before-and-after question: price changes, salary changes, traffic changes, and performance changes.
Example: moving from 950 to 1,025 is a 7.9% increase.
Keeping those question types separate is the main value of the tool. It removes the ambiguity before you even start.
If a rate moves from 40% to 44%, that is a rise of 4 percentage points. It is also a 10% relative increase. Those are both valid descriptions, but they are not interchangeable.
Percentage change is measured against the original value. Going from 100 to 150 is +50%. Going back from 150 to 100 is not -50%; it is about -33.3%.
A 20% rise followed by a 20% fall does not bring you back where you started. The second percentage applies to a different base.
“Sales rose 12%” only means something if the reader knows what the old value was and what is being compared.
A jacket priced at 85 with 30% off should be 59.50. If the till says something different, you can see immediately whether the discount has been applied to the correct base price.
If support tickets drop from 500 to 410, that is an 18% fall. That is a more useful statement than simply saying “tickets fell by 90”, especially when you are comparing teams of different sizes.
A score of 18 out of 24 is 75%. This is a simple example, but it is exactly the kind of conversion people repeatedly need in school, training, and internal assessment work.
If a 15% deposit is required on 2,400, the amount is 360. That is a “percentage of a number” question, not a percentage-change question.
A good quick check is to use 10% as a reference. If 10% of 80 is 8, then 15% of 80 should be a bit more than 8, not 40 or 0.8.
This tool handles plain percentage calculations. It does not calculate compound growth over multiple periods, country-specific tax treatment, or the wider business context around the numbers.
Percentage figures look authoritative even when they are wrong. A mistaken discount, a misleading progress figure, or a badly stated increase can all sound plausible at a glance. Choosing the right question type first is what prevents most of those errors.
Percentage change shows how much a value has increased or decreased relative to its starting point. Positive = increase, negative = decrease.
Yes. All inputs accept decimals and results are displayed without trailing zeros for readability.
This tool runs entirely in your browser. Nothing you type or paste is sent to any server — all processing happens locally on your device.