Miles are a currency your credit card issuer creates, and you earn them by spending money

When you use a rewards credit card, the issuer tracks how much you spend and deposits miles into an account tied to your card. The earning rate is fixed: you might get 1 mile per dollar spent, or 3 miles per dollar on certain categories like flights or dining. The issuer sets this rate, and it does not change based on how you use the miles later.

Miles are not the same as cash back. Cash back is a percentage of your purchase that goes directly to your statement or a bank account. Miles are a separate currency that lives in a rewards account, and you have to convert them into something else — a flight, a hotel stay, a gift card — to get value from them. If you never redeem them, they are worth nothing to you, though most cards let you keep them indefinitely.

The issuer owns the rules. They decide how many miles a flight costs, whether you can transfer miles to other people, and whether miles expire. Read your card's rewards terms before you sign up, because these rules vary widely between issuers and between different cards from the same issuer.

Key Takeaways

  • You earn miles at a rate set by your card issuer — typically 1 to 5 miles per dollar spent — and they accumulate in a rewards account you can view online.
  • Miles have no fixed cash value; what they are worth depends on what you redeem them for and which airline or hotel program you use them with.
  • Redeeming miles for flights usually costs between 7,500 and 50,000 miles depending on the route, distance, and how far in advance you book.
  • Some cards let you transfer miles to airline or hotel partners, while others restrict you to booking through the card issuer's own website.
  • Miles can expire if your account becomes inactive, so check your card's terms for the specific rules that explore to you.

How to redeem miles for flights and hotels

The most common way to use miles is to book a flight through your card issuer's travel portal or directly through an airline's website. You log into your rewards account, search for a flight, and instead of paying dollars, you pay miles. The number of miles required depends on the airline, the route, the time of year, and how far ahead you book. A short domestic flight might cost 7,500 miles; a long international flight might cost 50,000 or more.

Some cards also let you transfer miles to airline or hotel partners at a set exchange rate. For example, your card might let you convert 1,000 miles into 1,000 frequent flyer miles with United, or 1,000 hotel points with Marriott. This is useful if you have a specific airline or hotel loyalty program you prefer, but the exchange rate is usually not in your favor — you often lose value in the transfer.

Hotels work similarly. You can book through your card's travel portal, or some cards let you transfer miles to hotel loyalty programs. Hotel redemptions vary widely; a night at a budget hotel might cost 5,000 miles, while a luxury property could cost 50,000 or more.

What miles are actually worth in dollars

Miles do not have a set dollar value. What they are worth to you depends entirely on what you redeem them for. If you book a $300 flight using 25,000 miles, then each mile is worth about 1.2 cents. If you book a $600 flight using the same 25,000 miles, each mile is worth 2.4 cents. The same miles can be worth different amounts depending on your redemption choice.

This is why comparing rewards cards by their earning rate alone is misleading. A card that earns 2 miles per dollar is not automatically better than a card that earns 1 mile per dollar if the second card's miles are worth more when you redeem them. You have to know both the earning rate and the redemption value for the trips you actually take.

Industry analysts often estimate that miles are worth between 1 and 2 cents each on average, but this varies by airline, by season, and by how far in advance you book. Premium cabin flights (business or first class) tend to offer better value per mile than economy flights. Off-peak travel usually costs fewer miles than peak travel on the same route.

Earning miles faster through sign-up bonuses and category spending

Most rewards cards offer a sign-up bonus — a large number of miles deposited into your account after you spend a certain amount within a set timeframe, usually three to six months. A typical bonus might be 50,000 miles after you spend $3,000 in the first three months. This bonus is often worth more than the miles you earn from regular spending, so it is usually the biggest source of miles for new cardholders.

Beyond the sign-up bonus, you earn miles from everyday spending. Many cards offer higher earning rates in specific categories: 3 miles per dollar on flights and hotels, 2 miles per dollar on dining, 1 mile per dollar on everything else. Some cards offer the same rate on all purchases. The category structure matters if you spend a lot in one area — a heavy traveler benefits from a card with bonus miles on flights, while someone who eats out frequently might prefer bonus miles on dining.

A few cards let you earn miles on things beyond credit card purchases: transferring a balance, opening a new bank account with the same issuer, or using a shopping portal that connects you to partner retailers. These are usually minor sources of miles compared to sign-up bonuses and regular spending.

When miles expire and what happens to unused rewards

Most airline and hotel loyalty programs do not expire miles as long as your account stays active. "Active" usually means you have earned or redeemed miles within the last 12 to 24 months, or you have a co-branded credit card from that airline or hotel. As long as you use the card or the loyalty account occasionally, your miles stay in your account indefinitely.

However, some cards have their own expiration rules separate from the airline's program. A few cards expire miles if your account is closed or inactive for a set period. Read your card's rewards terms to understand the specific rules. If you are concerned about losing miles, the safest approach is to redeem them before your account becomes inactive, or to keep your card open even if you are not using it regularly.

If you close a credit card, the miles usually stay in the airline or hotel loyalty program attached to that card, not with the credit card issuer. You can still redeem them through the airline or hotel's website. The card itself is gone, but the miles remain.

How miles compare to cash back rewards

Cash back is simpler than miles: you earn a percentage of each purchase as actual money, usually credited to your statement or deposited into a bank account. There is no conversion step, no redemption portal, and no guessing about value. A 2% cash back card on a $100 purchase gives you $2, period.

Miles offer higher earning rates in specific categories — you might earn 5 miles per dollar on flights instead of 2% cash back — but that only matters if the miles are worth more than 2 cents each when you redeem them. If they are worth less, you are better off with cash back. If you rarely travel or do not want to track redemption values, cash back is usually the simpler choice.

The trade-off is flexibility. Cash back works for anything — you can use it to pay your statement, buy groceries, or save for anything you want. Miles only work for travel and travel-related purchases (and sometimes gift cards or merchandise), so they are less useful if your spending does not align with those categories.

Frequently Asked Questions

Do I have to pay taxes on credit card miles?

The IRS generally does not tax miles earned from credit card spending, because they are considered a rebate on your purchase rather than income. However, if you receive miles as a sign-up bonus without making a purchase, or if you transfer miles to someone else, the tax treatment becomes unclear. Consult a tax professional if you have a large number of miles or an unusual situation.

Can I sell my miles or give them to someone else?

Most airline and hotel programs do not allow you to transfer miles to another person, even a family member. Some programs have limited transfer options for a fee, but this is rare. Selling miles is against the terms of service for virtually all programs. If you have miles you will not use, your best option is to redeem them for someone else's ticket or to donate them to a charity program.

What happens to my miles if I close my credit card?

The miles stay in the airline or hotel loyalty program, not with the credit card issuer. You can still redeem them through the airline or hotel's website. However, if your card is the only way you have been keeping your loyalty account active, closing it might trigger inactivity rules that eventually expire your miles. Check the airline's or hotel's policy before you close a card.

Are premium cabin flights worth more miles?

Yes, business and first class flights cost significantly more miles than economy on the same route — sometimes two to four times as many. Whether they are worth it depends on your valuation of the miles and how much a paid business class ticket would cost. Some travelers find premium cabin redemptions offer better value per mile than economy, while others prefer to use fewer miles for economy and save the difference.

Can I use miles from different airlines together?

No. Miles are tied to a specific airline or hotel program and cannot be combined with miles from another program. However, some credit cards are co-branded with multiple airlines or let you transfer miles to several different programs, giving you flexibility in how you use them.