Make a percentage worksheet
- Choose percentage change, part of a whole, or a ratio split. The field labels change to match the question.
- Enter your numbers. For a ratio split, also enter the desired total. Read the formula before adding the result to your sheet.
- Label and add the calculations you want to compare. Copy an individual result and its steps, download the sheet, or print it.
Three questions, three formulas
Percentage change: (new − original) ÷ original × 100. Use it when comparing the same quantity at two points. Both inputs need the same unit. A zero original value is undefined, even when the new value is also zero.
Part of a whole: part ÷ whole × 100. A score of 18 out of 24 is 75%. Values greater than the whole produce more than 100%; the tool does not silently cap them. Signed inputs are supported as algebra, with a nonzero whole.
Split by a ratio: for A:B and total T, the first share is T × A ÷ (A+B), and the second is T × B ÷ (A+B). A 2:3 split of 100 is 40 and 60. Parts and total must be nonnegative, and at least one part must be positive. This splits a total; it does not find an unknown equivalent ratio or simplify integer ratios.
Keep the comparison meaningful
A rate changing from 10% to 15% moves 5 percentage points, or 50% relative to its original rate. Enter 10 and 15 in percentage-change mode for the second question. Keep the distinction in the worksheet label so the exported result answers the question you intended.
The worksheet keeps up to 100 labeled rows in tab memory, with the original inputs and formulas. Reloading clears the list. Results display up to 12 significant digits using browser arithmetic; very large or tiny calculations can exceed its number range. It does not infer financial meaning, round people into groups, or adjust your inputs to make a result fit.
Frequently asked questions
Is a change from 80 to 100 a 20% increase?
No. The difference is 20, but the original base is 80: 20 ÷ 80 × 100 = 25%. Changing from 100 back to 80 is a 20% decrease because the base changes.
What happens if the original value is zero?
Percentage change is undefined. Dividing by zero cannot produce a finite percentage. From 0 to 100, the absolute change is 100 units; it is not a 100% increase.
How are negative original values treated?
The formula divides by the signed original value. For example, −100 to −50 produces −50%. That sign does not establish improvement or decline in a business, profit, or other real-world outcome.
Does a ratio split round to whole items?
No. A 1:2 split of a total of 1 gives fractional shares. You need a separate allocation rule to distribute indivisible people or objects.