(WXIA) -- Sherean Allen is a self-professed Amazon junkie.
"I pretty much buy anything I can online," she said as she opened a recent shipment containing breakfast cereal, bathroom supplies and other household items. "If my son's brushing his teeth and I notice he's almost out of toothpaste, I just pull out my mobile app, click and order it in a second."
Online shopping increased 10 percent in the past year, and household goods are a growing category.
We compared prices on seven common household items from Amazon, Sam's Club, Costco and Walmart: brand name paper towels, coffee, diapers, batteries, cleaning wipes, ibuprofen and trash bags.
Since some of the sizes varied, we calculated the cost per unit: for example, Folger's coffee ranged from 21 to 39 cents per ounce.
Huggies diapers ranged from about 22 cents each to around a quarter.
Who had the lowest prices overall?
Costco came in first with the best prices on coffee, batteries, diapers and cleaning wipes.
Next was Sam's Club, followed by Walmart. Amazon had the overall highest prices on the seven items we checked, though it did have the lowest on paper towels and trash bags.
Still, the lure of that huge selection, quick shipping and convenience have made shoppers like Allen Amazon loyalists.
Keep in mind that an Amazon Prime membership, which features free two-day shipping, costs $99 per year, Costco memberships are $55 and Sam's club memberships are $45. Both Costco and Sam's Club charge shipping on some items. Walmart.com offers free shipping on purchases of $50 or more.
Here is a breakdown of the prices we per unit.
Sparkle Paper Towels (Cents Per Sheet)
Amazon - .0093
Sam's Club - .0097
Costco - .0123
Folger's Coffee (Cents Per Ounce )
Amazon - .33
Sam's Club - .23
Walmart - .29
Costco - .21
Glad Kitchen Trash Bags (Cents Per Bag)
Amazon - .152
Sam's Club - .157
Walmart - .152
Costco - .157
Duracell AA Batteries (Cents Per Battery)
Amazon - .46
Sam's Club - .37
Walmart - .49
Costco - .18
Huggies Diapers (Per Diaper)
Amazon - .24
Sam's Club - .24
Walmart - .24
Costco - .21
Lysol Wipes (Per Wipe)
Amazon - .072
Sam's Club - .040
Walmart - .041
Costco - .037
Generic Ibuprofen (Per Pill)
Amazon - .015
Sam's Club - .008
Walmart - .012
Costco - .010