It used to be simple. When you flew a mile on an airline, you would generally earn a mile in the airline’s loyalty program. Now, that’s almost never the case.

Almost all U.S.-based airlines have now switched to revenue-based mileage programs, meaning you earn miles based on how much you spend. And even for the airlines that pay based on the miles you fly, there’s typically an earning rate that’s applied to the number of miles flown.

All of this means that it’s a lot more complicated to figure out how many miles you’ll earn by flying. Here’s how to figure out how rewarding your next flight will be.

Revenue-based mileage programs

Revenue-based programs award miles for the amount you pay for a flight rather than the physical distance you fly. Generally, these mileage earnings are based on the price you pay before taxes and fees.

A decade ago, revenue-based airline programs were fairly uncommon in the U.S. JetBlue was one of the first U.S. airlines to launch a revenue-based program when it revamped its program in 2009. Southwest followed, with a program "enhancement" in 2011.

Then, the big airlines jumped on the bandwagon. Delta transitioned to a revenue-based system in 2015, and American Airlines and United quickly followed suit. Now, almost all major U.S. airlines operate a revenue-based program. However, programs differ a bit in how they award miles. We will get into the details below.

Mileage-based mileage programs

In some mileage-based programs, you’ll earn 1 mile per mile flown. In other programs, a ratio is applied to the number of miles flown to calculate the number of miles you’ll earn. The type of ticket you buy can affect the number of miles you’re awarded, with a first-class ticket paying more miles than an economy class ticket for the same flight.

There’s only one major U.S. airline that still operates this type of program, Alaska Mileage Plan (outside the U.S. a number of airlines still use distance-based programs).

How you earn miles on American, Delta and United

For better or worse, the three biggest U.S. airlines have very similar mileage earning systems. General members earn 5 miles per dollar of eligible spending on travel with the airline. Elite members earn a bonus on this base earning, with all three programs topping out at 11 miles per dollar for top-tier elites.

On Dec. 9, 2021, Delta became the first domestic airline to make basic economy fares ineligible for mileage earning. Basic economy flyers will no longer earn SkyMiles or any Elite Qualifying Miles, Dollars or Segments.

Figuring out eligible spending

The hardest part of the process can be figuring out the eligible spending amount, which usually includes the base fare and carrier-imposed fees (e.g. fuel surcharges). However, eligible spending doesn’t include taxes, airport fees, seat assignment fees, checked bag fees or any other fees that the airline might charge.

American, Delta and United display how many miles you’ll earn on their websites. Just log in to your mileage account, then start a flight search. Your potential mileage earnings for the flight will appear during the booking process. If you’re not logged in, the airline won’t factor in elite bonuses, so you may not get accurate information.

American Airlines displays mileage earnings on the final "Review and Pay" page if you’re logged into your account when booking a flight on aa.com. For example, here’s a Dallas-to-Atlanta flight that costs $24 total. Of that, $10 is taxes, leaving just $14 of eligible spending. General AAdvantage members earn 5 miles per dollar on eligible spending, which comes out to 70 award miles on this flight.

Delta doesn’t make you go quite as far into the booking process before revealing how many miles you’ll earn. When booking a Delta flight while logged into your SkyMiles account, you’ll see the earnings stated at the bottom of the "Trip Summary" page. For example, this $44 flight from Atlanta to Dallas has $34 of eligible spending. Delta also pays general members 5 miles per dollar of eligible spending, making this flight worth 170 SkyMiles.

For United, you can click "View MileagePlus earnings for this trip" on the final payment page. For example, this $99 United flight from Denver to Houston has $88 of eligible spending. At 5 points per dollar, a general member earns 440 award miles for this booking.

Earning as an elite member

If you’re an elite member with American, United or Delta, you’ll earn even more miles on your flight. Just as these three airlines all pay 5 miles per eligible dollar to general members, they all add the same percentage boost based on elite tier status. In each program, the lowest-tier elite earns a 40% bonus on the base earning rate, or 7 miles per dollar. Mid-tier elites earn a 60% bonus (8 miles per dollar), and mid-high elites earn an 80% bonus (9 miles per dollar). Top-tier elites earn a 120% bonus for a total of 11 miles per dollar:

Earning on partners

Although all three programs are revenue-based, that’s not necessarily the case when flying on their partner airlines. Earnings when flying on partners are generally based on the miles flown, the class of service and the fare class booked.

For example, here’s how American Airlines AAdvantage members earn award miles and elite-qualifying activity on British Airways flights:

However, the earning method depends on the flight number. If you book a British Airways flight with an American Airlines codeshare flight number, you’ll earn miles as if you were flying on American Airlines.

Elite members earn a 40% to 120% bonus on the base mileage earnings, but elite bonuses aren’t applied to cabin bonuses.

How you earn miles on Alaska Airlines

Alaska still awards Mileage Plan miles based on physical miles flown. But you still have a little work to do to figure out how many miles you’ll earn.

Calculating miles you’ll earn on an Alaska flight

To figure out the physical distance of an upcoming flight, we recommend using a tool like Great Circle Mapper. Enter an origin and destination airport to map the route and find out how far the flight is. For example, Seattle to Dallas/Fort Worth is 1,660 miles.

Next, find your booking cabin and fare class on your ticket confirmation. Generally, economy flights on Alaska earn 100% of miles flown — although very expensive tickets might get bonus miles. First-class tickets earn 100% base miles and 75% bonus miles.

That means most economy flights between Seattle and Dallas/Fort Worth will earn 1,660 award miles — no matter how much or little you spent on the ticket.

Earning as a Mileage Plan elite

Elite Alaska members earn a bonus on the base earning rate. Alaska has three tiers of elite status. Here are the bonus miles each earns:

MVP: 50% bonus.

MVP Gold: 100% bonus.

MVP Gold 75K: 125% bonus.

Earning on partners

Similar to Alaska-operated flights, you’ll earn award miles when flying partners based on miles flown. For example, here’s the Mileage Plan earning chart for American Airlines flights:

As with flights on Alaska, elites will earn an elite bonus on the base miles earned, but not the bonus miles for flying in particular cabins.

How you earn points on JetBlue

JetBlue’s "Blue Basic" fares — JetBlue’s form of basic economy — earn 1 base point per dollar. You’ll earn another 1 point per dollar by booking these fares through the JetBlue app or website, for a total of 2 points per dollar.

All other JetBlue fares earn 3 base points per dollar spent, with another 3 points per dollar for booking through the JetBlue app or website. That’s a total of 6 points per dollar for non-basic fares.

As with the other airlines, these points are earned on the base fare of the flight. Points aren’t earned on taxes, airport fees or other airline charges.

Earning as a Mosaic elite

JetBlue offers four levels of Mosaic elite status. Mosaic members can earn up to 9 additional TrueBlue points per dollar spent on all fares. That means you’ll earn 9 points per dollar spent on non-basic fares booked through JetBlue’s app or website.

How you earn points on Southwest

Similar to JetBlue, Southwest point earnings are based on both the amount spent and the fare type purchased. As Southwest demonstrates in the graphic below, fares earn points at the following rates:

Business Select: 12 points per dollar.

Anytime: 10 points per dollar.

Wanna Get Away Plus: 8 points per dollar.

Wanna Get Away: 6 points per dollar.

When you look at a specific flight on Southwest’s website, the airline does the math for you:

Earning as an A-List elite

Southwest has two levels of elite status: A-List and A-List Preferred. Members can also earn a Southwest Companion Pass, but this is earned separately from elite status.

Elite members earn bonus points on flights:

A-List: 25% bonus.

A-List Preferred: 100% bonus.

The bottom line

As you can see, figuring out how many points or miles you’ll earn from a flight can get complicated. For most major U.S. airlines, the key driver is the amount you’re paying for the flight excluding taxes and fees. Some airlines also apply a different earning rate based on the type of fare purchased.

Each airline program offers bonus miles for its elite members, although this bonus varies widely — from 25% bonus for Southwest A-List elites to 125% bonus for Alaska’s MVP Gold 75K elites.

Thankfully, you don’t need to break out a calculator. Most airlines show you exactly how many miles or points you’ll earn when you’re booking the flight.