Percentage of Total Calculator

Empty amounts are ignored. Numbers stay in your browser. The default rows are East 9,450 and West 15,000, which add to 24,450 — the same regional totals used in the pivot-table examples on this site.

Quick answer: a percentage of total is the part divided by the sum of the parts. In Excel or Google Sheets, with amounts in A2:A3:

=A2/SUM($A$2:$A$3)

Fill that down the column and format the cells as percentages. The $ signs freeze the total so row 3 still divides by A2:A3, not by a range that has slid down.

East 9,450 and West 15,000

Those two region totals add to 24,450. East’s share is 9,450 ÷ 24,450. In Google Sheets on 12 November 2026, =9450/24450 returned 0.38650306748466257, or about 38.6503%. West is =15000/24450, which is 0.6134969325153374. The two fractions add to 1.

The same idea works for more than two parts. For 120, 80 and 40 (total 240), =120/SUM(120,80,40) returned 0.5, and 80 returned 0.3333333333333333. A product split of 19,800 and 4,650 against a 24,450 total gave Widget a share of 0.8098159509202454, matching the earlier pivot table check.

This is not the same as a percentage change, which compares a new value to an old one. A share asks “how much of this pile is East?” A change asks “how much did East grow?”

Putting the formula next to a list

Keep the amounts in one column and the percentages in the next. If a label sits in column A and the amount in B, starting at row 2:

=B2/SUM($B$2:$B$10)

Widen the SUM when you add rows, or convert the list to an Excel Table so the total expands. A leftover Grand Total row inside the SUM range will double-count and shrink every share.

Displayed percentages are often rounded. Three equal parts shown as 33.3% add to 99.9% on the screen even though the exact fractions add to 100%. If you need a column that visibly adds to 100% at one decimal place, that is a rounding choice, not a different formula — and the last row is usually the one people adjust by hand, which I would not do in a sheet that still has to total the raw amounts correctly.

Things that quietly go wrong

A total of zero is #DIV/0!. Mixing a number that is already a percentage into the same SUM as currency will produce a share that is not what you meant. So will leaving one part out of the range, or including a subtotal and the details it already contains.

Absolute references matter once you copy the formula. =B2/SUM(B2:B10) without the dollar signs becomes =B3/SUM(B3:B11) on the next row, and the last row divides by a range that no longer holds every part.

Questions that come up

What is the Excel or Google Sheets formula for a percentage of total?

If the parts are in A2:A3, use =A2/SUM($A$2:$A$3) and fill down. The dollar signs keep every row dividing by the same total. Format the result as a percentage.

Why do my percentages not add up to 100%?

Rounding is the usual reason: 33.3% + 33.3% + 33.3% is 99.9% if you display one decimal. The underlying fractions still add to 1, which this calculator also reports. If they do not, a row is missing from the SUM or the total includes an extra number.

What if the total is zero?

The division is undefined, and a spreadsheet shows #DIV/0!. You cannot express a share of a total that is zero.