QUICK ANSWER
How much gas does a 500-mile road trip cost?
At 32 MPG, 500 miles uses about 15.63 gallons. At $3.20/gallon, fuel cost is about $50.00.
500 ÷ 32 = 15.625 gallons · 15.625 × $3.20 = $50.00
Use your real MPG
Highway fuel economy can differ from the EPA rating or dashboard estimate. Use the MPG you actually see on similar trips when budgeting.