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Gas Station Savings Decider

Determines whether driving out of your way to a cheaper gas station actually saves you money after accounting for travel fuel consumption.

Savings Estimate

Enter values above

Fuel cost eaten by detour0%
Gross savings at cheaper station
Gas burned driving round-trip
Net savings / loss
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TabSalary calculator guide

When cheaper gas is actually cheaper

A lower pump price does not automatically make a detour worthwhile. The relevant comparison is the discount on the gallons you plan to buy minus the fuel consumed on the extra round trip. This calculator isolates that fuel-only break-even point.

Written by the TabSalary editorial team · Last reviewed July 21, 2026

How the calculation works

Net savings = (local price − cheaper price) × gallons purchased − (round-trip miles ÷ MPG × local price)

  1. Calculate gross savings from the price difference multiplied by gallons purchased.
  2. Double the one-way detour distance to get round-trip miles.
  3. Divide round-trip miles by fuel economy to estimate fuel burned, then price that fuel.
  4. Subtract detour fuel cost from gross savings; a positive number means the trip saves fuel dollars.

Worked example

A station five miles away is 30 cents cheaper and you need 12 gallons. Gross savings are $3.60. A ten-mile round trip in a 30 MPG vehicle burns about one-third of a gallon. Valued at the $3.50 local price, the detour fuel costs roughly $1.16 after the calculator's rounding, leaving about $2.44 before valuing time or vehicle wear.

What this estimate does not include

  • Travel time, depreciation, maintenance, tolls, traffic, idling, and the value of your time are excluded.
  • Real-world fuel economy varies with speed, weather, load, route, and driving style.
  • If the cheaper station is already on your route, use only the additional distance created by the stop.

Use the result as a planning estimate, not as personalized financial, tax, legal, or investment advice.

Sources and further reading

Help & answers

Gas savings questions

Common questions about deciding whether a cheaper gas station is worth the drive.

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Each tool is free, runs in your browser, and explains the assumptions behind the result.

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