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Road Trip Fuel Cost Calculator

Enter your trip distance, MPG, and gas price — get the exact fuel cost for your road trip instantly. Free, no signup, works on any device.

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⚡ Quick Road Trip Calculator

Estimated Fuel Cost
How It Works

How to Calculate Road Trip Fuel Cost

The formula for road trip fuel cost is simple. You just need three numbers: your trip distance, your car's fuel economy (MPG), and the current gas price per gallon.

Fuel Cost = (Distance ÷ MPG) × Gas Price
Example: 400 miles ÷ 28 MPG = 14.3 gallons × $3.50/gal = $50.00

Step 1 — Find your trip distance

Use Google Maps or Apple Maps to get the exact mileage from your starting point to your destination. For a road trip with multiple stops, add up each leg of the journey. If you're doing a round trip, multiply the one-way distance by 2.

Step 2 — Know your car's MPG

Your car's MPG (miles per gallon) is listed on your window sticker or in your owner's manual. For highway road trips, use your highway MPG — it's typically 3–5 MPG higher than your city rating. If you've never checked, Gaslo's MPG calculator helps you measure your real-world fuel economy.

Step 3 — Get the current gas price

Check GasBuddy, Google Maps, or Waze for current prices along your route. If you're planning in advance, use the national average as a baseline. Gas prices vary significantly by state — California and Hawaii tend to be the most expensive, while Texas and Mississippi are typically the cheapest.

Step 4 — Multiply it out

Divide distance by MPG to get gallons, then multiply by the gas price. The quick calculator at the top of this page does all of this for you automatically.

Reference

Road Trip Fuel Cost Examples

Here are common road trip distances and estimated fuel costs at $3.50/gallon for different vehicle types:

Trip Distance Compact Car (32 MPG) SUV (25 MPG) Truck (18 MPG)
100 miles$10.94$14.00$19.44
250 miles$27.34$35.00$48.61
500 miles$54.69$70.00$97.22
1,000 miles$109.38$140.00$194.44
2,000 miles$218.75$280.00$388.89

Based on $3.50/gallon regular unleaded. Actual costs vary by route, driving style, and current gas prices.

Save Money

Tips to Reduce Fuel Costs on Your Road Trip

1. Drive at 60–65 mph instead of 75+

Fuel economy drops sharply at high speeds. Driving at 65 mph instead of 75 mph can improve your MPG by 10–15%, saving a meaningful amount of gas on a long trip. The U.S. Department of Energy estimates every 5 mph over 60 effectively costs you about $0.22 more per gallon.

2. Use cruise control on the highway

Consistent speed is more fuel-efficient than constant acceleration and deceleration. Cruise control keeps you at a steady speed, reducing fuel waste. On a long highway drive, this alone can improve fuel economy by 7–14%.

3. Plan your fuel stops in advance

Gas prices can vary by $0.30–$0.50 per gallon between states and between urban and rural areas. Use GasBuddy to map out the cheapest gas stations along your route before you leave. Filling up just before an expensive stretch (like entering California) can save $10–$20 on a large tank.

4. Pack light and remove roof cargo when not needed

Extra weight reduces fuel economy. A roof cargo box adds significant aerodynamic drag — studies show it can reduce MPG by 2–17% depending on speed. Remove it when you're not using it. For every 100 lbs of extra weight, you lose about 1% fuel economy.

5. Check tire pressure before you leave

Under-inflated tires increase rolling resistance. Check your tire pressure the morning before your trip (tires are most accurate when cold) and inflate to the PSI listed on the driver's door sticker — not the number on the tire sidewall.

FAQ

Frequently Asked Questions

How do I calculate road trip fuel cost?
Divide your trip distance by your car's MPG to get gallons needed, then multiply by the gas price per gallon. Example: 400 miles ÷ 28 MPG = 14.3 gallons × $3.50 = $50. Use the quick calculator above for an instant result.
How much does gas cost for a 500 mile road trip?
At $3.50/gallon: a compact car at 32 MPG costs ~$54.69, an SUV at 25 MPG costs ~$70, and a truck at 18 MPG costs ~$97.22. Enter your exact numbers in the calculator above for a precise estimate.
Does highway driving use more or less gas than city driving?
Less. Highway driving is typically 3–5 MPG more efficient than city driving because you avoid constant stop-and-go acceleration, which burns the most fuel. However, speeds above 65–70 mph start reducing efficiency again due to aerodynamic drag.
Should I fill up before or during a road trip?
Fill up before you leave if local prices are lower. During the trip, fill up when your tank hits the quarter-full mark — don't wait until empty, and don't pay premium prices at highway rest stops unless necessary. Plan stops at regular gas stations just off the highway.
Is Gaslo's road trip calculator free?
Yes — completely free, no signup required. The full trip calculator at gaslo.one also includes a built-in vehicle database with EPA MPG data so you don't have to look up your car's fuel economy manually.
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