It’s no secret that there are many ways to earn miles in addition to flying.Up there with the best of them? Simply doing your grocery shopping. In light of the changes many of us have had to make because of the pandemic, bonus miles are now also available when shopping with many of your favorite grocery delivery services.Credit cards offer rewards on grocery spending both in terms of cash back and miles and points. To see which card would best match your grocery shopping habits, check out our complete guide to the best grocery credit cards for 2021.Get the latest points, miles and travel news by signing up for TPG’s free daily newsletter.Over here in the U.K., we don’t have the same amazing 10x bonus point earning levels that there are in the U.S. However, I still managed to wrack up enough miles in the last year for a flight from London to New York, just by doing my food shopping.The supermarkets here in the U.K. are different from U.S. supermarkets, and with it the points premise is slightly different as well. Tesco and Sainsbury’s (two of the most popular supermarket chains) have their own loyalty programs and points currencies. Customers can then opt to use that currency in-store or convert them to partners’ currencies – in this case, Avios and Virgin Points.Here’s how I did it.American Express Membership RewardsAmount: 3,120 Membership RewardsMembership Rewards is the points currency of American Express. The points are a personal favorite of mine, as there are many ways to use them, and redeeming them is easier than you might think.Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.I earned the points by paying for my groceries bought at Sainsbury’s and Tesco with the U.K. version of The Platinum Card® from American Express. While I earn a mere 1 point per GBP spent, the American version earns a whopping 10x per dollar spent at U.S. supermarkets!On average, I spent around £60 per week on groceries with my Amex Platinum, which works out at 3,120 points annually. On the same card in the U.S., that would have worked out as 31,120 Membership Reward Points – that’s more than enough for a return flight to London from New York!Tesco Clubcard and Virgin PointsAmount: 5,585 Virgin PointsTesco’s loyalty scheme is the Tesco Clubcard which earns you 1 point for every pound spent. Already you can see that’s way less than you’d earn per dollar in the U.S.Over the course of the year, I converted my Clubcard Points into a total of 5,585 Virgin PointsSainsburys Nectar and British Airways AviosAmount: 5,000 AviosIn the same time period of about a year, I earned a total of 5,000 Avios by doing my grocery shopping at Sainsbury’s.For every 400 Sainbury’s Nectar Points I earn, I get 250 Avios, so the Avios soon start adding up.How does that get you to new york?In total I earned 13,705 miles just by doing my grocery shopping. I earned the amount in three different ways, and split across two airline loyalty programs. If I’d stuck to one airline loyalty program, I’d have been able to redeem a flight to New York, but I’m trying to earn points across both programs so I can keep my options open.For example, if I’d only shopped at Tesco, and converted my Membership Rewards to Virgin Points, I would have been able to redeem a one-way flight with Virgin Atlantic to New York. Only a few thousand more and I’d have had enough for a return trip, which is 20,000 Virgin Points in standard season (this goes up to 40,000 for a round-trip in peak season).On the other hand, if I’d only shopped at Sainsbury’s and converted my Membership Reward Points to Avios, I would have had enough for a one-way flight from London to New York. Thanks to BA recently introducing Reward Flight Saver pricing on some long haul routes, passengers can now choose from a selection of Avios + cash offers that suit their budget and Avios stash.You might wonder why I didn’t suggest the 6,500 + £200 ($277) option to be able to redeem a return ticket rather than just a one-way. That’s because the $554 (£200) in taxes and fees paid on top of the 13,000 Avios (valued at approximately $195) would, more often than not, cost more than cash return from London to New York. As you can see, round-trip prices with major carriers offering nonstop flights across the Atlantic start as low as £326 ($450) – a total of $299 dollars cheaper than what it would have been to redeem 6,500 Avios + £200 each way.Bottom lineI was able to earn enough points for a flight to New York just by going about my normal grocery shopping spending. I didn’t include all the other ways I earned points over the last year, as the focus of this piece was about the value of being clever about the way you do your grocery shopping.Put it this way: if a single guy using a relatively low point-earning U.K. credit card can earn 13,705 miles, just think how many miles a couple, or a family with kids, in the U.S. could earn by maximizing all the ways of earning points by grocery shopping when there are cards that offer as many as 10x points per dollar?