How Many Trash Bags Does a Warehouse Use?

Trash bags are bought by whoever notices the box is empty, which means almost nobody knows how many a site actually uses. A short count gives you the figure, and the figure decides how much to order and whether buying in bulk is worth it yet.

The counting formula

Usage is the number of bins, multiplied by how often each is emptied, multiplied by the days you operate.

• Bins — count every drum and bin that takes a liner: production, packing, offices, loading bays, the canteen.
• Changes per day — for each, how many times it is emptied. A packing-bench bin might be changed three times a shift; an office bin once a day, or less.
• Days per week — the days those bins are in use.

Do not guess. Walk the site once and write it down, or simply count the bags you pull from stock over two weeks.

A worked example

A packing warehouse has 12 large drums, each changed once a day, five days a week. That is 12 × 1 × 5 = 60 bags a week, or about 3,100 a year.

At our 1,000-bag price of $0.84 for the 3.0 mil bag, a year of supply is around $2,600. The 5,000-bag price of $0.75 would bring a year’s use down to about $2,300, a saving of roughly $300, but 5,000 bags is 83 weeks of supply at this rate. You would be paying for a year and a half of stock, and storing it, to save that $300. These are modest numbers, which is the honest picture: bin liners are a small cost, and the saving from buying well is real but not dramatic. Order for the next few months, not the next few years.

What 1,000 bags means in time

Divide the order by your weekly use. At 60 a week, 1,000 bags is nearly 17 weeks of supply, or about four months. That is a sensible order. At 10 a week it is almost two years, which is too long; at 200 a week it is five weeks, and you should be ordering more.

The break-even is roughly 15 to 20 bags a week. Below that, you would hold more than a year of stock, and an ordinary retail pack from a local supplier is the better answer for now.

Where to put them

1,000 bags at 3.0 mil is 20 cases of 50, and a case weighs about 10 kilograms. That is around 200 kilograms in total, so a reasonable shelf or a corner of a pallet bay rather than a storeroom. At the lighter 2.0 mil, 1,000 bags is 10 cases of 100.

Store the cartons off the floor, dry and out of direct sunlight. Polyethylene degrades slowly with heat and ultraviolet light, which is a problem over years rather than months, and a cold store makes film stiff. Rotate older cases to the front.

When to reorder

Set a trigger by quantity rather than relying on someone noticing. Multiply weekly use by your lead time in weeks and add two weeks of buffer. At 60 bags a week, a three-week lead time and a two-week buffer, reorder when you fall to 300 bags, which is six cases.

Check you are using the right bag first

Before ordering a year of anything, use the count to ask whether bags are being wasted. If bins are being changed half-empty or oversized bags are used where a smaller one would do, the number you have just measured is higher than it needs to be. Our guides on sizing bags to bins and why bags split are the quickest way to bring it down.