The even odd calculator checks a whole set of numbers in one go. Add numbers one by one or paste a list, then get a result for each one, a count of evens and odds, and a file you can download.
Check several numbers
What this calculator is for
Teachers use it to check a worksheet’s answer key, students to verify a set of exercises, and analysts to label a column of IDs before splitting data into two groups. Invalid entries (for example a decimal or a typo) are flagged individually and do not stop the rest of the list from being checked.
How to use it
- Type a number in each field. Select + Add number (or press Shift + Enter) for more fields, and × to remove one.
- Have a list already? Open Paste a list instead, paste numbers separated by spaces, commas or line breaks, and select Add to list.
- Select Check All Numbers. The summary shows how many are even, odd and not checked.
- Use Copy results, Download TXT or Download CSV to keep the output. CSV files open directly in Excel, Google Sheets and Numbers.
How each number is classified
Each entry goes through the same steps as the single Even and Odd Test: the text is checked to be an integer, then its remainder after division by 2 decides the label. The table lists that remainder so you can see why each number landed in its group.
Example: 14, 27, −8, 0, 3.5, 101
Even: 14, −8 and 0 (remainder 0). Odd: 27 and 101 (remainder 1).
3.5 is reported as “Not an integer” and excluded from the counts, giving 3 even, 2 odd, 1 not checked.
A quick check on your totals
The parity of a sum depends only on how many odd numbers it contains. Add up the list above (14 + 27 − 8 + 0 + 101 = 134) and the result is even because the list has an even number of odd values (two). Whenever your count of odd numbers is even, the total of the integers is even too.
Frequently asked questions
How many numbers can I check at once?
Up to 100 per check. For longer sequences of consecutive integers, the Even and Odd Numbers List handles up to 10,000.
Can I paste numbers with thousands separators?
In the paste box, commas separate values, so 1,000 would be read as 1 and 000. Paste 1000 instead.
What does the CSV contain?
One row per entry with the columns number, result and remainder. Text entries are escaped so they cannot run as spreadsheet formulas.
Are my numbers saved?
No. Everything happens in your browser, and closing the page discards the list.