The best credit card for people who love shopping on Amazon

More than 40% of online shoppers buy from Amazon at least once a month, according to a recent poll from NPR.

If you're one of them, you might have seen promotions for an Amazon credit card. The mega online retailer offers four types of credit cards. Select crunched the numbers to determine which of these options provides the biggest benefit to frequent shoppers.

Our No. 1 pick is the Prime Visa. Although this card requires users to have an eligible Amazon Prime membership ($139 annually, or $14.99 a month), the company's branded credit card offers the highest rewards return: 5% cash back at Amazon.com, Amazon Fresh, and Whole Foods Market. Plus, on Amazon Prime Day, you can earn an even higher cash-back rate when shopping with the card at Amazon. Since Amazon Prime has more than 200 million subscribers, many people already meet this requirement.

Below, we break down Amazon's four credit cards to help you choose the best card for your needs.

1. Prime Visa
2. Amazon Visa
3. Amazon Store Card
4. Amazon Prime Store Card

Who's this for? The Prime Visa, offered through Chase, rewards users with the highest unlimited cash-back rate of the Amazon branded credit cards Select analyzed. For all purchases made by Prime members at Amazon.com, Amazon Fresh, and Whole Foods, you get a robust 5% cash back. That's one of the key reasons this card was our No. 1 pick overall for online shopping.

In addition to the generous 5% cash back at those three retailers, the card offers users 5% back on Chase Travel purchases, 2% back on purchases made at restaurants, gas stations and drugstores. All other purchases earn 1% cash back. Plus, 10% back or more on a rotating selection of products and categories at Amazon.com.

If you're debating whether an Amazon Prime membership is worth the money, this card could help you decide: As a welcome bonus, cardholders can get a $100 Amazon Gift Card instantly upon approval exclusively for Prime members, which offsets the majority of the $139 annual membership your first year.

Amazon Prime membership gives you access to a number of perks, including free two-day shipping, access to Prime Video and exclusive discounts at Whole Foods.

That said, the Prime Visa doesn't have the most competitive welcome bonus, and you can do better than 2% back at restaurants, gas stations and drugstores with other rewards cards if those are big spending areas for you.

*First year rewards total incorporates the points earned from the welcome bonus. When we calculated the returns for the Prime Visa, we assumed the cardholder would do 75% of their grocery shopping at Whole Foods Market; 25% of their clothing and housekeeping supplies shopping at Amazon. You may earn a higher or lower return depending on your spending habits.

Who's this for? If you don't have an Amazon Prime membership but still frequently use the website to shop, another option is the Amazon Visa. This credit card does not require a Prime membership and still offers 3% back at Amazon and Whole Foods, along with the 2% back at restaurants, gas stations and drugstores.

New cardholders get a $50 Amazon gift card once their application is approved. Cardholders can also benefit from no foreign transaction fees and select travel benefits, such as travel accident insurance, auto rental collision damage waiver and lost luggage reimbursement.

If you later decide to become a Prime member, you'll be upgraded to the Prime version of this card.

*First year rewards total incorporates the points earned from the welcome bonus. When we calculated the returns for the Amazon Rewards Visa Signature Card, we assumed the cardholder would do 75% of their grocery shopping at Whole Foods Market; 25% of their clothing and housekeeping supplies shopping at Amazon. You may earn a higher or lower return depending on your spending habits.

Who's this for? If you're not a Prime member but still looking to make a big purchase on Amazon, the Amazon.com Store Card, offered through Synchrony, gives you access to interest-free financing for 6, 12 or 24 months.

Special financing

• Pay no interest on Amazon.com purchases of $150 or more if the entire purchase amount is paid in full within 6 months.
• Pay no interest on Amazon.com purchases of $600 or more if the entire purchase amount is paid in full within 12 months.
• Pay no interest on select Amazon.com purchases of $800 or more if the entire purchase amount is paid in full within 24 months.

Equal monthly payments

• Make equal monthly payments for 6 months on Amazon.com purchases of $150 or more and pay no interest.
• Make equal monthly payments for 12 months on Amazon.com purchases of $600 or more and pay no interest.
• Make equal monthly payments for 24 months on select Amazon.com purchases and pay no interest.

During the special financing period, you're still required to make at least the minimum monthly payment. In order to get the full benefit, you need to pay off the entire balance before the intro period ends, or else you'll incur all the interest you accrued during the 6-, 12- or 24-month period (known as deferred interest). Once the intro period ends, there's a high 27.49% variable APR.

There are not any cash-back rewards for spending, but you can get a $60 Amazon gift card once you are approved for a credit card.

Who's this for? The Amazon Prime Store Card, available to those with a Prime membership, has the same promotional financing offers as the Amazon Store Card above, as well as cash-back rewards.

With this card, you can earn 5% back on Amazon.com purchases but, unlike with the Prime Visa and Amazon Visa, you do not earn cash back at Whole Foods, restaurants, gas stations, drugstores or any other purchase.

Cardholders have to choose between earning 5% back or using a promotional financing period. For example, if you purchase a 65-inch flat screen TV for $900, you're eligible for a financing plan in which you would not pay interest for two years. But if you take advantage of the financing, you wouldn't receive the 5% cash-back reward (worth $45) on that $900 purchase.

To determine which Amazon card will put the most money back in your pocket, Select compared the four Amazon cards on a range of features, including cash-back rewards, annual fee, welcome bonus, introductory and standard APR, balance transfer fee and foreign transaction fees, as well as factors such as required credit and customer reviews when available.

Select teamed up with location intelligence firm Esri. The company's data development team provided the most up-to-date and comprehensive consumer spending data based on the 2019 Consumer Expenditure Surveys from the Bureau of Labor Statistics. You can read more about their methodology here.

Esri's data team created a sample annual budget of approximately $22,126 in retail spending. The budget includes six main categories: groceries ($5,174), gas ($2,218), dining out ($3,675), travel ($2,244), utilities ($4,862) and general purchases ($3,953). General purchases include items such as housekeeping supplies, clothing, personal care products, prescription drugs and vitamins, and other vehicle expenses.

Select used this budget to estimate how much the average consumer would save over the course of a year, two years and five years, assuming they would attempt to maximize their rewards potential by earning all welcome bonuses offered and using the card for all applicable purchases. All rewards total estimations are net the annual fee.

It's important to note the value of a point or mile varies from card to card and based on how you redeem them. When we calculated the estimated returns, we assumed that cardholders are redeeming cash back for a typical maximum value of 1 cent per point or mile. (Extreme optimizers might be able to achieve more value.)

Our final picks are weighted heavily toward the highest five-year returns, since it's generally wise to hold onto a credit card for years. This method also avoids giving an unfair advantage to cards with large welcome bonuses.

While the five-year estimates we've included are derived from a budget similar to the average American's spending, you may earn a higher or lower return depending on your shopping habits.

Information about the Prime Visa, Amazon Visa, Amazon Store Card, Amazon Prime Store Card has been collected independently by Select and has not been reviewed or provided by the issuer prior to publication; if you purchase something through Select links, we may earn a commission.