Aldi is shockingly cheaper than Dollar General

Dollar General is known for its low prices.

The discount chain claims that it's 20% cheaper than major grocery stores and 40% cheaper than convenience stores.

But there's at least one retailer that crushes Dollar General when it comes to the price war: Aldi.

The German grocery chain's prices are 21% cheaper than Dollar General's, according to a recent price check by Deutsche Bank.

Analysts compared the prices of 40 similar items at Aldi, Walmart, and Dollar General at stores in Northern New Jersey.

The Aldi bill was $95.73, Walmart's was $112.97, and Dollar General's was $115.87.

Aldi's prices also beat Save-A-Lot's and Kroger's. In another price check in Nashville, Deutsche Bank found that Aldi was 10% cheaper than Save-A-Lot and 22% cheaper than Kroger.

Dollar General, with about 12,500 locations, is a much bigger chain than Aldi, which has just 1,500 stores in the US.

Despite its relative size, Aldi poses a serious threat to dollar stores and Walmart, according to Deutsche Bank analysts. Aldi is planning to open another 500 stores over the next two years.

"All retailers need to treat Aldi (and at a later date Lidl) as a meaningful threat - and to be dismissive will likely prove to be a tactical/strategic error," the analysts wrote in a research note.