Last-minute flight plans? Here's how to save money on your business trip or getaway

One of the best ways to save money on a flight is to plan ahead. But sometimes, you don't have the luxury of advance notice. Here's how to find cheap last-minute flights, whether you're traveling for a family emergency, a business trip on short notice or a spontaneous escape.

Use a flight map

Google Flights and Skyscanner have handy map tools that can help you find the cheapest flight.

If your destination is set in stone, use the map to compare fares at nearby airports as well. It may be cheaper to fly into a location a few hours away and rent a car to reach your final stop.

If your destination is open-ended -- like "anywhere with a beach" -- use the map to pick the most economical locale. Select your dates and home airport(s), and then scan the map for an affordable flight. Google Flights will even show you potential destinations; all you need to do is pick your travel dates and interests, whether they be wildlife, food, beaches or nature.

Call the airline

A handful of airlines still offer bereavement fares, which could help take the financial sting out of last-minute travel for a funeral. To get the discount, you have to book the flight by phone and typically need to start travel within seven to 14 days. Be prepared to provide the name of the relative and the name and phone number of the relative's doctor or funeral home.

Alaska Airlines, for example, will knock 10% off its published fares for passengers traveling due to the death of an immediate family member, according to Halley Knigge, a spokeswoman for the carrier. This also applies to Virgin America, which was acquired by Alaska Air Group.

Delta Air Lines and Air Canada also offer special rates for those traveling due to a death in the family.

However, there may be cheaper deals elsewhere, so compare the bereavement rates with regular fares from other airlines using sites such as Kayak or Last Minute Travel.

Fly during undesirable hours

"Go on a red-eye or crack-of-dawn flight," says Elizabeth Avery, the founder of the travel website Solo Trekker 4 U. These flights tend to have unfilled seats and often will be less expensive than midday flights.

A red-eye trip from the Washington, D.C., area to San Diego, for example, was nearly $130 cheaper than other options for that route, according to a recent search for flights available within seven days.

Tap your rewards

If you can't find an affordable fare or skip the trip, consider redeeming credit card rewards or airline miles to subsidize your flight.

Not sure whether to use rewards or cash?

You can calculate the value of your rewards for a given flight using this formula: (ticket price - taxes and fees) ÷ rewards cost. Then multiply that number by 100 to find out your rewards value.

Here's an example: A flight that costs $250 (with $20 in taxes and fees) or 25,000 miles would equal 0.92 cents per mile. That's below the average value of rewards and miles from a variety of programs, so consider using cash.

But if the same flight was $500 (with $20 in taxes and fees) or 25,000 miles, it would work out to 1.92 cents per mile. That's a good case for redeeming your miles, as it exceeds the average value of most rewards programs.