Just because you’re on a tight budget doesn't mean you need to give up the occasional getaway. If you're trying to plan an affordable vacation in the U.S., Wanderu can help. The travel site will find you all the places you can get to from your city for under $20.

Wanderu took the largest 50 cities in the U.S. and calculated the cheapest average bus and train fares departing from those locations, and filtered all the destinations that a traveler could reach for under $20.

The fare filtering was based on average fares for routes over a 30-day period, so there's no guarantee that you’ll be able to find a $20 ticket for every single bus from Boston to New York, even if the cheapest average fare is only $12.48. To get those truly cheap tickets, you'll probably have to be flexible with the dates and times you're willing to leave. You're not going to get a dirt-cheap express train ticket for the next day during rush hour on a holiday weekend. But if you want to leave on a bus in the middle of the night or early in the morning a few weeks from now, you can score a ticket at rock-bottom prices.

Some bus operators also offer elusive $1 fare deals to the first few passengers to book a seat, and Wanderu will tell you if that's an option, though it can't guarantee that you'll actually be able to snag one of those tickets.

The Wanderu cheap-fare aggregator is available for all the typical big cities you'd expect—New York, Boston, Chicago, Washington, D.C.—but it will also find you tickets departing from smaller cities, like Mesa, Arizona and Virginia Beach, Virginia. In some cities, there may not be a whole lot of options. There are only two destinations to choose from if you're leaving from Virginia Beach, for instance. But the search might inspire you to visit somewhere new.

If your city isn't on the list, you can tweet @GoWanderu and mention your location, and the Wanderu team will find you the cheapest routes.

Start your search here.