How much milk is at home? Where are those darn chips that are on sale? What checkout line is going to be the fastest? The supermarket can be a giant time suck — if you’re not smart about it. Luckily, these folks are basically geniuses when it comes to the grocery store. Steal their brilliant tips and shave off dozens of precious minutes from your trips.

Photo: Dan Dalton/Getty Images

You might have a designated day — and even time — that you prefer to get your shopping done, but what happens if you find yourself near a store or in need of one or two items on an off day? Caroline Turben, mom of two and Extravagant Gardens blogger, always has her shopping list on her. "I use the notes section on my iPhone and I just keep a running list," she says. "As I deplete things, and as I know what meals I'm going to make, I add to it." This ensures she can make any spur-of-the-moment stop at a store a productive one.

Photo: Westend61/Getty Images

There are few bigger wastes of time than standing in the dairy aisle trying to remember if you have enough milk. If you don't have time to make a list before you hit the store, take advantage of your phone's camera instead. "Take a photo of the fridge shelves before you head out," suggests organizing expert Jamie Novak. While you’re at it, snap pics of your pantry too. This way, you can check your phone to jog your memory of what’s at home.

Photo: LDProd/Getty Images

"The quickest way to check out a circular is to focus on the front and back of the ad," says Jordan Page, the blogger behind Fun Cheap or Free. "That's where the best deals are. The inside is typically just fluff." Page says she usually finds deals on meat, canned food and fresh produce. She'll buy extra and freeze (or shelve) whatever her family won't be able to eat right away.

Photo: Tetra Images/Getty Images

Just like you, sometimes grocery stores run out of ingredients. "Some people will take the time to go to another market," says Samantha Elkrief, a health and wellness coach. If the item you need is a central ingredient to a recipe, going elsewhere might be worth it, but Elkrief says flexibility is key. "If I need cashew butter but can't find it, I'll use almond butter or peanut butter. If I need Swiss chard but the store is out or it doesn't look fresh, I'll use kale. If I need pears, I know I can often use apples."

Photo: kone/iStock

"We've gotten used to going to larger stores, but we just don't need 28 different choices of peanut butter!" says Darla DeMorrow, a certified professional organizer. "People are tired when they get home, and adding more decisions to their day can lead to analysis paralysis, which is when it takes longer to come to a decision." Don't bombard yourself with options. And smaller doesn't have to mean pricier. DeMorrow's go-to small stores? Trader Joe's and Aldi.

Photo: Dan Dalton/Getty Images

You’re finally ready to check out, but which line should you get on? The one with a couple of people each buying a handful of items or the line with one person ahead of you with an overflowing cart? It should be the latter — the math proves it. According to Dan Meyers, Ph.D. (he studies math education and loves problems like this one), every person in front of you adds 48 seconds just by having to check out, whereas additional items only add 2.8 seconds. "Therefore, you’d rather add 17 more items to the line than one extra person!" he writes.

Photo: Noel Hendrickson/Getty Images

It sounds nice, in theory, to let someone else do the work while you zone out or check your phone. But Future You will thank you when you get home if you bag your own groceries. "I always put the frozen items together, the cold items together, bread and chips together, the produce together, heavier items together, and I try to keep the very fragile items (like tomatoes) in a bag with just a few items," Maynard says. Then, when she gets home, she can unpack like items at once. If there is a bagger at work in your line, sneakily trick him into bagging how you would, by placing items on the belt in your desired groups.

Photo: Kartina Wittkamp/Getty Images